While it is obviously best to prevent or deter crime before it occurs, this is not always possible. Despite the fact that modern policing tactics, such as problem-oriented policing and intelligence-led policing, have contributed to massive crime decreases since the 1990s, agencies still have to grapple with the challenge of solving crimes that cannot be prevented.[i]
When criminal offenders avoid detection and punishment, it signals to the rest of society that the justice system is impotent and may encourage future offending. This applies not only to the most heinous crimes such as homicide and rape but also applies to violations of people’s fundamental sense of security in cases of burglary and robbery.
The available evidence strongly suggests that agencies should always be mindful of the fact that the first officers or deputies on the scene play a crucial role in solving these crimes. Officers’ actions upon arriving are often the difference between a case becoming solved or going unsolved.
Burglary and Robbery Cases
One study conducted by the Police Executive Research Forum examined burglary and robbery cases across three years within three large law enforcement agencies. This study discovered that, of the cases cleared by arrest, most were cleared through the initial investigation conducted by the first patrol officers on the scene. A much smaller number of cases were cleared later through follow-up investigations by detectives. Analysis of all of the solved cases revealed what investigating techniques were most effective at clearing a case through an arrest. The most techniques were close cooperation between patrol officers and detectives, neighborhood canvasses looking for witnesses, use of informants, and the collection and analysis of physical evidence.[ii]
A study by the Police Foundation examined the length of time it took to solve a burglary, robbery, and theft cases in Rochester, New York. This study found that close cooperation between patrol officers and detectives in locating witnesses and physical evidence was a major factor in clearing these cases quickly.[iii]
Violent Crimes and Homicides
One study examined case clearance rates for violent crimes in four cities across two years. This study found the most effective actions the first officers on the scene could take to help solve the case were to secure the scene to protect physical evidence, search for eyewitnesses, and request assistance from other officers, detectives, or crime scene technicians. After the scene was secure, the most effective officer actions included searching for additional witnesses, collecting physical evidence, and submitting evidence for forensic analysis. Additionally, the more training the officers and detectives had received in criminal investigation techniques, the higher their case clearance rates.[iv]
Finally, a three-year examination of homicide cases in Boston revealed found that specific actions by patrol officers increased the clearance rates of homicides by 18%. These actions included quickly securing the scene, rapidly summoning detectives and crime scene technicians, locating physical evidence for the investigators, and continuing to look for, and interview, witnesses in the days following the homicide. Regarding the actions of the detectives, the most influential actions they could take to solve the case involved finding witnesses, collecting physical evidence, and having that evidence forensically analyzed.[v]
These four studies paint a consistent picture about what is needed in order to increase criminal case clearance rates. Strong cooperation and sharing of responsibilities between patrol officers and detectives is crucial. Patrol officers play a major part in the process by securing the scene, protecting potential evidence, locating witnesses at hand, and continuing to search for additional witnesses and informants over the days following the crime. Detectives, patrol officers, and crime scene technicians together play a joint role in locating, collecting, and analyzing physical evidence. Finally, criminal investigation training plays a pivotal role in equipping officers to perform these functions effectively, and giving them the confidence to seek justice for victims of crime.
[i] Hoover, L. T. (2014). Police Crime Control Strategies. Clifton Park, NY: Delmar.
[ii] Eck. J. E. (1983). Solving Crimes: The Investigation of Robbery and Burglary. Washington, DC: Police Executive Research Forum.
[iii] Bloch, P., & Bell, D. (1976). Managing Criminal Investigations: The Rochester System. Washington, DC: The Police Foundation.
[iv] Wellford, C., & Cronin, J. (1999). An Analysis of Variables Affecting the Clearance of Homicides: A Multistate Study. Washington, DC: Justice Research and Statistics Association.
[v] Braga, A. A., & Dusseault, D. (2017). Can homicide detectives improve homicide clearance rates? Crime and Delinquency, 1-33.
 Hoover, L. T. (2014). Police Crime Control Strategies. Clifton Park, NY: Delmar.
 Eck. J. E. (1983). Solving Crimes: The Investigation of Robbery and Burglary. Washington, DC: Police Executive Research Forum.
 Bloch, P., & Bell, D. (1976). Managing Criminal Investigations: The Rochester System. Washington, DC: The Police Foundation.
 Wellford, C., & Cronin, J. (1999). An Analysis of Variables Affecting the Clearance of Homicides: A Multistate Study. Washington, DC: Justice Research and Statistics Association.
 Braga, A. A., & Dusseault, D. (2017). Can homicide detectives improve homicide clearance rates? Crime and Delinquency, 1-33.