Job of a Police Officer: The Basic Rules of Policing

Here are the basic rules of policing:

Definitions:

Probable cause to search:  probable cause to search a place or thing exists if there is a “fair probability” or “substantial chance” that the object of the search is now located there.

Probable cause to arrest: probable cause to arrest a suspect exists if there was a “fair probability” or “substantial chance” that he committed or is committing a crime. 

Probable cause to seize evidence:  probable cause to seize evidence exists when “the facts available to the officer would warrant a man of reasonable caution in the belief that certain items may be contraband or stolen property or useful as evidence of a crime”.

Reasonable suspicion to detain:  reasonable suspicion to detain a suspect exists if there is a “moderate chance” that he committed or is committing a crime.

What Information Will (and will not) be considered:
Objective circumstances: probable cause is based mainly on the objective circumstances known to the officers.

Circumstantial Evidence: probable cause may be based partly or entirely on circumstantial evidence.

Officers’ opinions and reasonable inferences:  the courts will consider an officer’s opinion as to the meaning or significance of facts if, (1) the opinion was based on his training and experience, and (2) it appeared to be reasonable.
          Expertise not required: an officer’s opinion may be considered even if he had not qualified as an expert witness in court.
          Unsupported conclusions: unsupported opinions are irrelevant.
Officers’ state of mind: irrelevant.
“innocent” circumstances: probable cause may be based on “innocent” circumstances (i.e., circumstances that so not directly implicate the suspect in criminal activity) so long as the circumstances, when considered together, they were sufficiently suspicious. 
Baseless “facts” and hunches:  in sharp contrast to hard facts are vague or unsubstantiated tidbits of information, such as the following:
Unsupported conclusion of fact: irrelevant.
Conclusion of law: an officer’s legal opinions are irrelevant; e.g., “I have probable cause,” or “my informant is reliable.”  These are legal determinations that are solely within the province of a judge.
Hunches: although hunches have a place in police work,, they are irrelevant in determining the existence of probable cause.

Facts inadmissible in court
Hearsay: may be considered, but the value of hearsay depends on whether there is reason to believe the information is accurate or that the source is reliable.

Privileged information: maybe considered.
Information obtained illegally: may not be considered if obtained in violation of a suspect’s constitutional rights; e.g., illegal search.

Uncommunicated information: as a general rule, information will not be considered in determining the existence of probable cause or reasonable suspicion unless it had been aware of information that was possessed by others.

Post-search/seizure pooling: a search, arrest, or detention without sufficient justification cannot be validated later by showing that it would have been justified if the officers had been aware of information that was possessed by others.

“collective knowledge” rule: although the courts do not permit post-arrest or post-search pooling of information to establish probable cause, they will ordinarily presume (in the absence of testimony to the contrary) that two or more officers pooled their information beforehand if they were generally communication as to developments in the case.

How the facts are analyzedIntroduction: in the past, many courts made their probable cause rulings by carefully analyzing each of the facts upon which the officers relied, and then subjecting each fact to a hypercritical analysis based on a “complex superstructure of evidentiary and analytical rules.” but in 1983, in the landmark case of Illinois v. Gates, the U.S. Supreme Cour rejected this type of analysis and replaced it with a “totality of circumstances”

Totality of the circumstances:
Under the “totality” standard, the courts base their rulings on an assessment of the overall force of all relevant circumstances.  This means that judges must not isolate each face, belittle its importance or explain it away, and then conclude that probable cause did not exist because none of the facts were very incriminating.
Unreliable information: still, information is virtually useless unless there is reason to believe it is accurate.

Common sense: the court in Gates also ruled that, in determining whether probable cause existed, the various circumstances must be evaluated in light of common sense.

Combinations of circumstances: although probable cause may be based on a single incriminating circumstance, it is usually based on combinations of less powerful circumstances. 

Utilizing probable theory: with each additional circumstance-with each “coincidence of information” the chances of having probable cause increase exponentially.

What Probability is required:
Introduction: it is often assumed that probable cause requires at least a 51% probability because anything less would not be “probable.” Although the U.S. Supreme Court has refused to assign a probability percentage (because it views probable cause as a non-technical standard based on common sense, not mathematical precision), it has said indicated that the following probabilities will suffice.
Probable cause: probable cause requires neither a preponderance of the evidence, nor “ any showing that such belief be correct or more likely true than false.”   Thus, it requires something less than a 51% chance.

Possibility of innocence explanation: if probable cause exists, it is immaterial that there might have been an innocent explanation for the suspect’s conduct, or that the evidence being sought might not be located in the place that the officers searched.

Other indicators: the courts often note that probable cause requires less than a prima facie showing, but more than a good faith belief.
Reasonable suspicion: the required probability is “considerably less” than a preponderance of the evidence; i.e., considerably less than a 50% chance.

Offers’ uncertainty: if reasonable suspicion exists, it is immaterial that the officers has some doubt as to the suspect’s guilt.

Mistakes by officers
Mistake of fact: if probable cause was based in whole or in part on information that was subsequently determined to be untrue, the information may nevertheless be considered if officers reasonably believed it was true.

Mistakes of law
Mistake as to crime committed: if officers have probable cause to arrest the suspect for some crime, it is immaterial that they mistakenly arrest him for a crime that was not supported by probable cause.

Mistake that suspect was arrestable: if officers were wrong in their conclusion that probable cause to arrest existed, or that the suspect’s conduct constituted a crime, the arrest is unlawful.
Accusatory vs. Investigative questioning: investigative questioning is much less likely to result in a detention than accusatory questioning. 
Investigative defined: Investigative questions imply that officers are merely exploring the possibility that the suspect might have committees a crime.  While such questioning is “potentially incriminating,” is is also potentially exonerating. 
Accusatory defined: Accusatory questions communicate to the suspect that the officers are fairly certain that he committed a crime, and that their objective is to obtain an admission.  Accusing the suspect of having committed a crime is apt to result in a detention or arrest.
Ignoring a refusal: A de facto detention or arrest will result if officers persisted in questioning the suspect after he declined their request.
Grounds to Detain: grounds to detain exist in either if the following circumstances:
Reasonable suspicion: officers reasonably believed that the suspect was committing a crime, was about to commit on. Or had committed an unsolved  crime.
Passenger in stopped car: the detainee was an occupant of a vehicle that was stopped on grounds that officers reasonably believed that another occupant was committing a crime, was about to commit one. Or had committed an unsolved crime.
De Facto Arrest:  a detention becomes a de facto arrest if its scope or intrusiveness were, (1) beyond that which is associated with investigative detentions, and (2) unnecessary under the circumstances. (3)  A de facto arrest is unlawful unless there was probable cause to arrest. 
Consequences: a de facto arrest is illegal unless probable cause existed. No “least intrusive means” test: in the past, some courts ruled that a de facto arrest would result if officers failed to employ the least intrusive means of pursuing their investigation.  The “least intrusive means” test has been abrogated.  (I have to double check this statement.  I have seen case laws ruled on by the Supreme Court that requires the "least intrusive means")  Update: Here is case law that contradicts this statement: "In order for investigative detention of defendant to be valid, investigative methods employed should be least intrusive means reasonably available to verify or dispel officer’s suspicion in short period of time. U.S.C.A. Const.Amend. 4"

Duration: officers who have detained a suspect must carry out their duties diligently.
Time limit: although there is not maximum time limit, officers must promptly terminate the detention when they have completed their duties.  
Arrest Procedure: there are certain technical requirements set by  California statute with which officers should comply when they make an arrest. 
They are as follows:
Notification: officers must “inform the person that he is under arrest. This can be accomplished directly of by any other words of conduct that would reasonably indicate to a reasonable person that he was under arrest.
Specific authority: officers must notify the suspect of their authority to make the arrest but because this simply means it must have been apparent to the suspect that he was being arrested by an officer, this requirements  is satisfied if the officer was in uniform of displayed his badge. 
Specify Crime:
Federal Law: Although giving notice is “good police practice,” it is not required.
California Law: officers must notify the suspect of the crime for which he is being arrested only if he asks.
Need for force:
Resisting arrest: in most cases, the need will be based solely on the suspect’s physical resistance to arrest but if the suspect was not resisting, there would be no need for any force, other than the de minimis variety.
Not resisting but not under control even though a suspect is not actively resisting, some degree of non-deadly force may be deemed reasonable if he was not yet under the control of the arresting officers.  This is especially true if there was probable cause to arrest him for a violent felony. 
Threats to officers: it is relevant that the suspect was known to be armed and dangerous, and the he threatened violent resistance to arrest
Threat to others: the need for force becomes much greater if the suspect’s resistance also constituted a serious and imminent threat to the safety officers or others; e.g., vehicle pursuit.
Proportionate response by officers: having established the existence of a need for force, the courts will next look to see whether the amount of force utilized was commensurate with that need;  e.g. hard pulling, control hold, pepper spray, utilizing a properly-trained and controlled police dog. 
Tasers: the electric shock caused by tasers is classified as non-deadly force,  but not a de minimis force. This is because the affect of such a shock on a suspect is quite painful, that the affect is not always predictable, and that come people have died after being tased.  As a result, some courts have classified tasers as “intermediate” force, which requires a demonstrably greater need than non-deadly force. Still, the use of a taser is often deemed a reasonable response when there is significant resistance, especially if officers had been unable to control the arrestee by other means.
No Probable Cause:  if probable cause did not exist, any statements or evidence obtained as a result of the arrest may be suppressed if the taint from the unlawful delay had not been attenuated. 


Specific testimony required: the courts will not place much significance on the “high crime area” circumstance unless officers can explain how they determine there was a serious crime problem in the area.

Arrest for 148: if grounds to detain exist, flight may provide probable cause to arrest for obstruction officers in the discharge of their duties.

Probable Cause to Search
Requirements: having probable cause to arrest a suspect does not automatically provide probable cause to search him, his vehicle, or home for evidence of the crime. Instead, it requires proof of the following:
(1)        the evidence exists: there must be reason to believe the sought-after evidence exists. 
(2)        Location:  there must be reason to believe that the evidence was taken to, or produced, at the location of the search.
(3)        It’s still there: there must be proof that the evidence was not subsequently moved or used up.

The Evidence Exists: the existence of the evidence may be proven directly, circumstantially, or by reasonable inference. Direct evidence
Plain view: proof that evidence exists is often based on a plain view observation by an officer or other person.

Information from owner: the existence of stolen property may be established by the owner of the property; e.g., robbery or burglary victim provided a description for the property that was stolen. 

Actual instrumentalities: the existence of evidence may be inferred from circumstances indicating that such evidence was used in the commission of the crime; e.g., because the murder weapon was a “medium caliber handgun,” the existence of such a weapon was reasonably inferred.

Burglar tools and stolen property: because officers found burglar tools in the suspect’s possession, they reasonably believed that a laden pillowcase he was carrying contained stolen property.

Reasonable inference based on training and experience: in the absence of direct or circumstantial evidence, the probable location of evidence may be established by reasonable inference; i.e., “the normal inferences as to where a criminal might likely hide incriminating evidence.”
Vehicle Searches
Probable cause searches:
Introduction: if officers have probable cause to believe there is contraband or other evidence inside a vehicle, they may search for it without a warrant. This is sometimes called the “automobile exception” to the warrant requirement. 
No “necessity” requirement: if probable cause exists, it is immaterial that officers could have secured the vehicle and applied for a warrant; or that the search was not contemporaneous with the arrest of the driver.
Increased importance: because of the Supreme Court’s decision in 2009 to virtually eliminate vehicle searches incident to the arrest of an occupant (i.e., Belton searches), the automobile exception has become much more important.  This is because many searches that would have been upheld in the past under Belton can be upheld under the automobile exception.  Specifically, when officers have probable cause to arrest an occupant of a vehicle, they will often have probable cause to believe that the vehicle contains fruits and instrumentalities of the crime.

Get a warrant/ Although a warrant is not required when officers have probable cause, officers should consider applying for one if they are unsure whether probable cause exists and if they have time to do so. 

When Permitted:
Requirements: there are three requirements:
(1)        probable cause: officers must have probable cause to believe there is contraband or other evidence inside the vehicle; i.e., they must have been aware of facts that could have supported a warrant to search the vehicle. 864
(2)        vehicle: as used here, the term “vehicle” is broadly defined to include cars, vans, motorcycles, boats, even bicycles.
(3)        Vehicle in public place: officers must have been able to access the vehicle without violating the suspect’s reasonable expectation of privacy.  Thus, a search would not be permitted if the vehicle was parked in the suspect’s garage or inside some other building in which he reasonably expected privacy.  Driveway: a vehicle that is parked in the driveway of the suspect’s home, or in the carport of an apartment complex is in a public place.

What may be searched: officers may search any place or thing in which the sought-after evidence could reasonably be found. Although the scope is broad, there are a few twists.

Searching occupants: officers may not search the clothing of occupants unless they had probable cause to believe that the evidence was, in fact, located there. Limited Probable cause: If officers now that the evidence is located only in a certain area or container, they may search that area or open that container but they may not search elsewhere.  For example, if officers are tracking a container of drugs, and if they see someone put the container in a vehicle, and search it.  But they could not search anywhere else unless they had probable cause to do so.

Search for indicia: a search of other areas for indicia ought to be permitted if, as is usually the case, officers had probable cause to believe that indicia would tend to prove the identity of the person who controlled the vehicle.

search after impound: officers may conduct the search on the street or they may impound it and conduct the search later.
Invetory Searches:
Purpose of search : unlike investigatory vehicle searches whose objective is to find evidence of a crime, inventory searches are classified as “community caretaking” searches because their objectives are as follows:
Make a record: make a record of the property inside the vehicle so as to, (1) provide the owner with an accounting, and (2) protect officers and their departments from false claims that property in the vehicle was lost, stolen, or damaged.
Make safe: protect officers and others from harm if the vehicle contained a dangerous device or substance.
Summary of requirments: vehicle inventory searches are permitted if the following circumstances existed:
(1)        towing reasonably necessary: towing the vehicle must have been reasonably necessary under the circumstances.
(2)        Standard search procedures: the search must have been conducted in accordance with departmental policy or standard procedure.
Towing reasonably necessary: because an inventory search can be conducted only if officers have take legal custody of the vehicle (albeit temporarily), the first requirement is that is must have been reasonably necessary to tow or impound it this does not mean that towing must have been imperative or essential.  It must simply be justifiable.Generally
No “least intrusive means”test: towing will not be deemed unreasonable merely because there was a less intrusive was to protecting the vehicle or its contents; e.g., locking the vehicle.
 Standard procedure not required: some courts have said or implied that “reasonableness” is not the test-that towing is permitted whenever it was conducted in accordance with standard procedure.  This is wrong.
Standard procedure not irrelevant: it is relevant that the officers were required or permitted to tow the vehicle under the circumstances because departmental policies are usually the result of a thoughtful consideration of the issues they address. 
Officer discretion is permitted: a reasonable departmental policy does not become unreasonable merely because it gave officers some discretion in determining whether to tow under the circumstances.

Mixed motivations: if towing was reasonably necessary, it is immaterial that the officers’ decision to tow was based in part on their suspicion that the vehicle contained evidence.

 Towing authorized by vehicle code: the vehicle code contains several sections that permit towing under circumstances that usually qualify as reasonably necessary.
Traffic hazard: the vehicle constituted a traffic hazard or obstruction.
Abandonment: the vehicle had been abandoned.
Driver incapitated: the driver was incapacitated by injuries or illness.
Driver arrested + reasonably necessary: while the vehicle code authorizes an impound when officers have arrested the driver or other person in control of the vehicle, 901 towing would be permitted only if it was reasonably necessary.
Legally parked, safe: towing would ordinarly be unreasonable if the vehicle was legally parked in a safe place and secured.
Passenger can take car: there was probably be no need to tow a vehicle if the arrestee wanted to turn over to a properly licensed and insured driver on the scene.
Standard procedure: towing would not be justified merely because it was “standard procedure”
Threat of theft or vandalism: thowing would ordinarily be reasonable if the vehicle was away from the arrestee’s home, especially if it was in a high-crime area where there existed a real threat of theft or vandalism, or the car was in an isolated area, or the car would not be secured.
Driver cited for 14601, 12500: the driver was given a notice to appear for a violation of Vehicle Code 14601 or 12500.
Passenger willing to drive: the question arises: may officers tow the registered vehicle if there is a licensed and insured passenger who is willing to drive it while the unlicensed driver rides in the passenger seat? See this endnote,
Expired registration: the Vehicle Code authorizes towing if, (1) the vehicle is on the street or public parking facility; and (2) the registration expired over six months earlier, or the registration sticker or license plate ws issued or antoher vehicle or ws forged.  In such a case, the Vehicle Code states that the agency that towed the vehicle may not release it until the owner has provided proof of current registration and a valid driver’s license.
Protecting the vehicle and its contents: even if the Vehicel Code does not expressly authorize towing, officers may do so if towing was reasonably necessary to protect it or its contents from theft or damage.
Towing from private property: under some circimstances, it may be reasonably necessary to tow a vehicle from private property or a public parking lot.
Towing forfeited vehicle: a vehicle was subject to forfeiture.
Standard search procedures: the second requirement for condiction a vehicle inventory search is that the scope and intensity of the search must have been restricted by means of “standardized criteria or established routine.” Generally
Purpose of requirement: when a police department adopts a standardized policy governing the search of the contents of impounded vehicles, the owners and occupants of those vehicles are protected against the risk that officers will use selective discretion, searching only when they suspect criminal activity and then seeking to justify the searches as conducted for inventory purposes.”
“reasonableness” is not the issue: while officers must prove that towing was reasonably necessary, they need not justify the decision to search because, as noted above, the courts recoginize that there are several good reasons for searching every towed vehicle.
How to prove existence of policy: the most common way of proving that a search was conducted in accordance with standard procedures is to present a copy of the policy (if it was written) or present testimony from an officer that the department had implemented a policy-written or unwritten-on how  inventory searches must be conducted.
Example of officers testimony
Written departmental policy
General policy requirments
General parameters are sufficient: a department’s written policy need not mandate the precise scope of the search or set forth exactly what officers may and may not search but it must limit the search to what is necessary “to produce an inventory.”
Partial list is sufficient: the policy need not require a listing of every object in the vehicle.
Thorough search: the policy may require a “through” search.
Officer discretion is permitted: the policy may permit officers to exercise discretion in determining what to search, but officers must exercise their discretion based on community caretaking objectives-not investigative needs.
No Damage: the policy may not authorize officers to damage or destroy parts of the car.
CHP form 180: in lieu of a written policy, many law enforcement agencies in California satisfy the “standardization” requirement by mandating that their officers complete a CHP 180 form which the California highway patrol provides to all officers in California,  this form requires, among other things, that officers list all “property” in the vehicle, including radios, tape decks, firarms, tools, and ignition keys.  It also requires a listing of all damage to the vehicle.

Unwritten departmental policy: in the absence of a written departmental policy, it may suffice that there existed an unwritten departmental policy or standard procedure for conducting inventory searches that sufficiently restricted the search.

Officer’s standard policy: in the absence of a departmental policy, it may be sufficient that the search was conducted in accordance with the officer’s standard procedure. (I have read case law that has contradicted this statement)
Protective Searches:
When permitted: a protective vehicle search (aka “ vehicle frisk”) may be conducted if the following circumstances existed:
(1)        lawful detention: an accupant of the vehicle must have been lawful detained. 
(2)        “Weapon” inside: there must have been reasonable suspicion to believe that a weapon was inside the vehicle.   
All of the infornation to this point was from California Criminal Investigation 2010 Edition.  It is published by the District Attorney's office for Alameda County.  This book is designed for police officers to help them get convictions.  It is also good to know what police are legally bound to do...Probable Cause to Arrest (includes reasonable suspicion to detain) 
Definitions
Probable cause to arrest: there are 2 definitions in current use, although there is not appreciable difference between the two.

Fair probability: probable cause to arrest exists if there was a “fair probability” or “substantial chance” that the suspect committed a crime (the trend is to apply this definition because it incorporates the more recent “fair probability” standard upon which probable cause to search is based.)

“honest and strong suspicion”: the older definition is that probable cause to arrest exists if the facts known to the arresting officer would have lead a person of ordinary care and prudence to believe and conscientiously entertain an “honest and strong suspicion” that the person had committed a crime.

Reasonable suspicion to detain: while probable cause exists if there is a “fair probability,” the lesser standard of reasonable suspicion exists if there is a “moderate chance.”

To detain people: reasonable suspicion to detain a person exists if officers were aware  of facts that reasonably indicated he was committing a crime, had committed one, or was about to commit one.  The courts also say that reasonable suspicion exists when the circumstances were merly consistent with criminal activity.

To detain property: reasonable suspicion to detain property (e.g. to secure it while seeking a warrant) exists if officers “possess specific and articulable facts warranting a reasonable belief” that the item is evidence of a crime.

More of the Basics:

Arrest “for investigation”: officers cannot arrest people “for investigation” of a crime or “on suspicion” in hopes that something might turn up.  This is because probable cause requires a reasonable belief that a person actually committed a crime, not that he might have done so.

Suspect’s Location: The courts have consistently ruled that officers cannot detain or arrest a person merely because they saw him at or near a public place in which criminal activity is prevalent.   Still, it is a relevant circumstance, often highly incriminating.

High Crime Area: A suspect’s presence in a “high crime area” will not justify a detention. It is , however, a relevant circumstance in light of other circumstances, especially if officers or witnesses saw him engaging in conduct that is associated with the type of criminal activity that is prevalent in the area.