a non-partisan police board to help govern the police force, a strict merit system for promotions within the department, and an aggressive recruiting drive with higher police salaries to attract professionally qualified officers. Despite such reforms, police agencies were led by highly autocratic leaders, and there remained a lack of respect between police and the community. During the professionalism era of policing, law enforcement agencies concentrated on dealing with felonies and other serious crime, rather than focusing on crime prevention. Following urban unrest in the 1960s, police placed more emphasis on community relations, and enacted reforms such as increased diversity in hiring. The Kansas City Preventive Patrol study in the 1970s found the reactive approach to policing to be ineffective. The cost of policing rapidly expanded during the 1960s. In 1951, American cities spent $82 per person on policing. Adjusting for inflation, police spending increased over 300% by 2016, to $286 per person. In the 1990s, many law enforcement agencies began to adopt community policing strategies, and others adopted problem-oriented policing. In the 1990s, CompStat was developed by the New York Police Department as an information-based system for tracking and mapping crime patterns and trends, and holding police accountable for dealing with crime problems. CompStat, and other forms of information-led policing, have since been replicated in police departments across the United States. Powers of officers Law enforcement officers are granted certain powers to enable them to carry out their duties. When there exists probable cause to believe that a person has committed a serious crime, a misdemeanor in their presence, or a select-few misdemeanors not in their presence, a law enforcement officer can handcuff and arrest a person, who will be held in a police station or jail pending a judicial bail determination or an arraignment. In 2010, the FBI estimated that law enforcement agencies made 13,120,947 arrests (excluding traffic violations). Of those persons arrested, 74.5% were male and 69.4 percent of all persons arrested were white, 28.0 percent were black, and the remaining 2.6 percent were of other races. A law enforcement officer may briefly detain a person upon reasonable suspicion of involvement in a crime but short of probable cause to arrest. Merely lawfully detaining a person—in and of itself—does not deprive a person of their Fourth Amendment right against unlawful searches. Federal, state, and local laws, and individual law enforcement departmental policies govern when, where, how, and