How Profiling Works

A man standing in front of large computer monitors.
"Profiler," a popular 1990s TV show, centered around a detective with the Violent Crimes Task Force. Colin Anderson Productions pty l / Getty Images

As the stars of true-crime documentaries, TV series and Hollywood thrillers, criminal profilerĀ­s have one of the best-known law enforcement jobs in the world. Basic profiling -- identifying the perpetrator of a crime based on an analysis of crime and the way it was committed -- is a common investigative tool. But some fear that police departments have taken profiling too far, harassing or even arresting people because of certain characteristics they might have in common with criminals -- or worse yet, because of their skin color. Others argue that in an age of terrorism and violent crime, we can't afford not to examine people based on crime patterns, even if that means suspicion based on race.

In this article, we'll look at the different types of profiling, see how police officers and criminal investigators create and use profiles and learn about the controversy surrounding the practice.


The most basic kind of profiling is a Be On the Lookout (BOLO) or All-Points Bulletin (APB). You're probably familiar with these, although you might not have heard it referred to as a profile.

An APB is a description of a specific suspect accused of committing a specific crime or crimes, usually based on eyewitness accounts. For example, following a bank robbery, police might interview suspects and review surveillance camera footage before releasing the following APB:

Suspect was last seen in a dark blue Ford pick-up truck. He was wearing a red T-shirt and black jeans. Suspect is described as a white male, 5-feet 10-inches tall and thin with receding blond hair. He has a tattoo of a snake on his left forearm.

Including a suspect's skin color is common, and not usually controversial. It is simply a physical description based on visual evidence gathered at the crime scene. It doesn't make any judgments about other people with white skin (or with snake tattoos and receding blond hair, for that matter).

The next step in profiling is the psychological profile. Investigators create this profile in the absence of physical evidence or eyewitness descriptions, or to supplement such descriptions. They take what they know about an unknown suspect and his actions and try to generate additional information. For example, if a serial murderer has been killing the female employees of a law firm, profilers might find it likely that the killer is a male former employee or client of the law firm.

Other evidence, such as notes left by the killer, the location of the killing, or the state of the crime scene can allow profilers to develop "educated guesses." These guesses might include things like the suspect's education level, psychological traumas he has suffered or where he lives. They are not always 100 percent accurate, and sometimes they can be rather vague. However, if the police have no idea who the suspect might be, it gives them somewhere to start looking. For example, interviewing former employees of the law firm might turn up more concrete clues that lead to direct evidence of the killer's identity.

Next, we'll look at predictive profiling.


Predictive Profiling

Instead of seeking a particular suspect based on evidence, predictive profiling attempts to guess which people are likely to commit a crime that hasn't yet occurred.
Image courtesy Jim/Morguefile

With predictive profiling, criminal profiling gets more controversial. Instead of seeking a particular suspect based on evidence at a specific crime, predictive profiling attempts to guess which people are likely to commit a crime that hasn't happened yet.

This isn't a revolutionary idea by itself. Police officers don't just react to crimes: They patrol, observe and try to spot suspicious behavior that could mean a crime is going to take place. Few people would question an officers' right to investigate a suspicious situation or question a suspicious person. Even when police departments use their criminal profiles as a justification for searches and arrests without warrants, those practices have been upheld by the Supreme Court.


Here's an example. State troopers are patrolling a stretch of highway known to be frequented by drug traffickers. The officers know from previous experience that drug traffickers often use rented cars (usually large sedans or SUVs), travel in the very early morning, and put the spare tire in the backseat to leave more room in the trunk for drugs.

At 4:00 a.m., an officer notices a car that fits this profile. The driver is not breaking any major traffic rules, but the trooper pulls the car over anyway, hoping to spot some evidence that could lead to a search of the car. This is considered profiling. The practice of noting criminal tendencies and creating a written profile is sometimes attributed to Florida Highway Patrolman Bob Vogel, although it was probably carried out by others at the same time or prior to Vogel's use of "cumulative similarities."

This kind of profiling can occur when the high-level officials create a policy and program that instructs officers to investigate people who fit a predetermined profile. It can also be part of an unofficial policy, an aspect of the police department's culture passed down from veteran cops to newcomers on the force. Sometimes it simply results from an officer's experience. After years on the job, he has learned what signs might indicate criminal activity.

To determine if such a profile justifies a warrantless arrest or search, the officer must be able to describe the specific factors that led him to believe the suspect was a criminal. A hunch or a feeling won't stand up in court. The following statement probably would:

The suspect appeared nervous and made several contradictory statements. In the back seat, I could see a shoebox full of 35mm film canisters, which drug couriers frequently use to store drugs. The car smelled like air freshener spray, which is often used to cover up the smell of illegal drugs. I spotted the suspect driving slowly up and down a block I know to be frequented by drug dealers.

That kind of profile is not only legal, it's considered good police work.

Some profiling practices come under legal fire because they might violate the U.S. Constitution. Two amendments specifically relate to profiling activity. The Fourth Amendment reads, in whole:

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no warrants shall issue, but upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

Probable cause means that police can't search a home, car or person without some kind of justification -- usually, a reasonable belief that they will find evidence of a crime there, or stop a crime in progress.

Under most circumstances, a police officer can't determine this on his own. He needs a search warrant from a judge, or consent from the person being searched. The main question surrounding profiling is this: If a person fits a criminal profile, in the absence of any other evidence of a crime, does that by itself constitute probable cause? In the case of United States v. Sokolow, the U.S. Supreme Court did decide that a "totality" of evidence leading officers to conclude that the suspect is probably engaged criminal activity is enough to justify an arrest and a search.

The Fourteenth Amendment reads, in part:

No state shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any state deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.

If police officers use criminal profiles that include race as factor, they violate both the Fourth and the Fourteenth Amendment.


Probable Cause Analysis

During a traffic stop, an officer can take several different actions that require different kinds of probable cause for them to be legal. Here we'll examine each step and break down the elements of probable cause.

  1. Pulling over a vehicle To legally pull someone over, an officer needs to have witnessed a traffic violation or another crime committed by someone in the car. He can also check the license plate number to see if the car is stolen or if there are arrest warrants out for the registered owner. If the car and its occupants fit a criminal profile, the officer can make a stop as long as he can describe specific factors that fit the profile. The race or skin color of the driver and occupants can't come into play, however.
  2. Questioning the suspect Once the officer pulls over a vehicle, he doesn't necessarily have to write a ticket. If the vehicle seems suspicious, the officer may just want to question the occupants, check their licenses against the department database and look inside the car. He can look at anything in plain view in the car. However, he does not have sufficient cause yet to enter and search the car. To do so would violate the Fourth Amendment protection against unreasonable search and seizure. However, if this preliminary investigation adds more weight to the officer's initial suspicion, he may have probable cause for an arrest and search. Again, this depends on the presence of specific factors in the profile, not just a "feeling," and race cannot be a factor. Image courtesy Once a suspect gives his consent, police officers can conduct a full search of his car.
  3. Consent to search If the actions of the suspects or the contents of their car raise further suspicions, the officer can ask the driver for consent to search the car. No one is ever required to say yes, but if they do, the officer needs no additional cause. The suspect has waived his Fourth Amendment rights, and the officer can conduct a full search. The officer is not required to tell the suspect that he can refuse consent (at least, not under federal law -- some states may have laws requiring this notification). This aspect is controversial because not everyone is aware of their right to refuse consent, and many people say yes out of fear or the feeling that the officer will do the search anyway.
  4. If consent is refused, the officer may detain the suspects for a reasonable amount of time. In 2005, the U.S. Supreme Court decided that using a drug-sniffing dog around the outside of a vehicle does not require a warrant nor any specific suspicion or probable cause, and does not violate the Fourth Amendment. If the dog "alerts" to the presence of drugs, that creates enough probable cause for a full search, without consent or a warrant. The "reasonable" amount of time provision is vaguely defined, although wait times up to 90 minutes have been allowed by federal courts [ref].
  5. Full search with probable cause The alert of a drug-sniffing dog, or seeing drugs or weapons sitting in plain sight inside the car are the most commonly accepted forms of probable cause. If the officer performs any of these actions without probable cause, then any evidence gathered as a result will not be allowed court. This could make it very difficult to successfully prosecute the suspect.


Racial Profiling

Racial profiling is a form of predictive profiling in which one of the factors (or the only factor) officers consider is the skin color or race of the suspect. Keep in mind that we are not talking about "rogue cops" with racist attitudes. Of course, racism exists in law enforcement just as with any large group of people. The real controversy erupts when police departments have policy-level profiling systems that include race as a factor, or a department-wide culture that teaches and reinforces the practice. Some people claim that racial profiling is blatant, institutionalized racism that leads to unfair harassment of minorities, while others claim that racial profiling either doesn't exist (i.e., police officers harass criminals, and if they happen to be minorities, that isn't the officers' fault) or that it is a necessary tool that simply reflects reality.

Separating fact from opinion can be difficult, because the same facts are used by both sides of the debate to support their own point of view. Opponents of racial profiling cite the disparity between the percentage of black inmates in the U.S. prison population and the percentage of the overall black population as a sign that blacks are unfairly targeted by police. U.S. census data for 2000 indicates that blacks make up 12.3 percent of the U.S. population, while Department of Justice statistics indicate that roughly 40 percent of all prison inmates are black [ref]. A similar disparity can be found among Hispanics. But some suggest that these statistics merely indicate that blacks and Hispanics are more likely to commit crimes.


Statistical analysis is even more difficult. According to those who say racial profiling doesn't happen, there are too many variables that would need to be taken into account to accurately compare general populations to prison populations. Even if traffic stops, roadside searches or arrests are broken down by race, these stats might be skewed because police make more traffic stops at times of day when more minorities are driving, or minorities might have a greater tendency to violate traffic laws. Higher accident and accident fatality rates are often cited as evidence of this. Advocates also point out that if racism were at the heart of minority stop and arrest rates, minority police officers would have different statistics than white officers. In fact, black cops on average pull over the same number of black drivers as white cops do [ref].

The most high profile case of systematic racial profiling was uncovered in New Jersey in 1999. An analysis of New Jersey State Trooper practices was conducted by the state attorney general, revealing that blacks and Hispanics were pulled over and searched many more times than non-minority drivers. In fact, 80 percent of all traffic stops conducted by New Jersey State Troopers during a 10-year period were stops of minority drivers. The report also found that a "macho," elitist culture existed within the state trooper ranks [ref]. Although department policy officially forbade racial profiling, reports from many troopers indicated that it was common for veteran troopers to "coach" others on its practice. Authorities assigned federal monitors to the troopers. In 2006, a report suggested that New Jersey had eliminated racial profiling actions completely, but whether or not they would still need federal monitors remained in question.

The New Jersey scandal brought profiling practices across the country into the spotlight. While Drug Enforcement Agency (DEA) training materials pointed out that racial profiling was unethical and against agency rules, DEA intelligence passed to agents and police departments frequently contained information on the national origin of potential suspects, as well as racial information [ref]. The New Jersey District Attorney's office issued a statement, declaring that law enforcement officers should not use race as a factor in any way during any step of the process of stopping and investigating a potential suspect. Essentially, cops should be blind to race, ethnicity and skin color (except when they are trying to match a person to a description of a specific suspect).

Departmental policies are supposed to aid law enforcement by examining trends in criminal activity. However, they have had the unintended consequence of creating a hostile situation for members of minorities who were innocent. Such policies would be considered civil rights violations, and many police departments have adopted policies specifically outlawing the practice. Twenty-two states have laws that ban racial profiling of motorists.


Post-9/11 Profiling

Airline passengers have gotten used to stricter security measures at airports.
Image courtesy Federal Aviation Administration (FAA)

After the September 11, 2001 attack on the United States (and subsequent terrorist attacks in the United States and elsewhere), the country is particularly sensitive to airport security screenings. Critics say that a disproportionate number of "Arab-looking" people have been detained, searched or questioned at airport security checkpoints. Some people claim this only makes sense, based on the ethnic backgrounds of the 9/11 attackers. However, such practices would violate civil rights law, and at least one expert has pointed out that focusing only on Middle-Eastern people would do more harm than good. Raphael Ron, former security head at Israel's Ben Gurion Airport, has stated, "The worst attack on Ben Gurion was carried out by Japanese in 1972. If we focus on ethnic groups, we will miss what the enemy already understands: using a non-Arab person to carry out an attack might succeed" [ref].

In the months immediately following 9/11, the American-Arab Anti-Discrimination Committee brought to court several cases involving people of Arabic descent who were removed from flights despite having passed other security checkpoints. Courts determined that the pilot's discretion to remove objectionable passengers cannot be exercised simply because of a passenger's ethnic origin or race. Still, the threat of terrorism made many Americans accept this tactic. Transportation Safety Authority rules have since been changed to clarify that racial profiling at airport security checkpoints is not legal, and newer security systems are designed to be race-neutral, focusing instead on behavior patterns.


For lots more information on profiling and related subjects, check out the links on the next page.

Lots More Information

Related Articles
More Great Links

  • Aaron, Lawrence. "State police still need oversight on racial profiling.", July 14, 2006. 5JmZnYmVsN2Y3dnFlZUVFeXk2OTYwODk3
  • "Are Airlines Violating Civil Liberties Because of Worries of Terrorism?." American Morning transcript. June 5, 2002
  • Amnesty International: Racial Profiling Laws in Your State.
  • Donnelly, Sally B. "A New Tack for Airport Screening: Behave Yourself.", May. 17, 2006.,8599,1195330,00.html
  • Evans, Catherine Donaldson. "Terror Probe Changes Face of Racial Profiling Debate.", October 01, 2001.,2933,35521,00.html
  • Fickes, Michael. "Exposing Hostile Intent." Transportation Security, Nov 12 2003.
  • Fink, Sheri. "Reasonable Doubt." Discover Magazine, July, 2006.
  • Harris, David A. "Profiles in Injustice." W. W. Norton & Company, May 2003. ISBN 1565848187.
  • MacDonald, Heather. "Are Cops Racist?" Ivan R. Dee, January 25, 2003. ISBN 156663489X.
  • "Newsbrief: Supreme Court Allows Drug Dog Vehicle Searches Without Cause.", January 28, 2005.
  • QT-P3. Race and Hispanic or Latino: 2000 Data Set: Census 2000 Summary File 1 (SF 1) 100-Percent Data Geographic Area: United States. U.S. Census Bureau. DEC_2000_SF1_U_QTP3&-ds_name=DEC_2000_SF1_U&-_>
  • U.S. Department of Justice: Criminal Offenders Statistics
  • United States v. Sokolow
  • Verniero, Peter. "Interim Report of the State Police Review Team Regarding Allegations of Racial Profiling." New Jersey State Police, April 20, 1999.