Cold cases refer to crimes that have gone unsolved for years and that have no active leads that investigators can pursue. According to a Scripps Howard News Service study of the FBI Uniform Crime Report, nearly 185,000 homicide/manslaughter cases went unsolved during the 28-year period between 1980 and 2008. That’s an average of nearly 6,000 unsolved murder cases every year in the United States—despite advances in everything from online investigative techniques to forensic science.
Clearance rates for homicides vary widely, according to location. For example, in 2008, Chicago managed to solve just 35 percent of its murders, while in San Diego, 94 percent of all murder cases were solved. The national clearance rate has also fallen, from around 90 percent in the 1960s to well below 65 percent in recent years.
To combat the problem of unsolved homicides, many of the nation’s larger police departments have implemented cold case units that are staffed with the most highly skilled investigators. Cold case units are now prevalent among state and city police departments. Many state trooper cold case investigative units also provide support to police and sheriff’s departments at the local level.
Cold Case Investigations: The Mission and the Operations
Cold case investigations within a state or local police department are organized with a team of experienced and highly skilled investigators, all of whom work to investigate unsolved homicides, missing persons cases, police-related shootings, and unidentified persons cases. Cold cases are defined as cases that are unsolved after a specific period of time (usually a year), as well as those with no identifiable leads. Detectives may also investigate other types of cases as deemed worthy by department heads.
A cold case investigation begins when detectives review a case to determine if new technology or new evidence exists that may help solve the case. Cold cases are generally reviewed every time additional information about the case becomes available.
Detectives in cold case investigations utilize the newest technologies and employ community policing partnerships when working cases. For example, recent advancements in DNA technology and other forensic techniques have allowed cold case investigators to reopen latent cases. These police investigators, during the course of their investigation, often spend their time inventorying evidence, seeking information from the investigators who were previously assigned to the case, re-interviewing witnesses or suspects, and working closely with forensic scientists. This systematic review of cold cases allows investigators to assemble and deploy resources and increase their chances of success.
Investigators within a cold case unit must establish a number of partnerships and locate new and viable leads, which may be a difficult process. Therefore, the most experienced investigators within a police department usually work cold case investigations.
Cold case unit investigators also serve as advocates for victims and bring peace to the loved ones of an individual who was killed or is missing. It is therefore common for detectives to provide families with victim advocates while working the case.
Job Duties of a Cold Case Investigator
Cold case detectives are responsible for a large number of critical duties, including:
- Supervising the collection of physical evidence
- Interviewing witnesses, family members, and suspects
- Evaluating the validity of new evidence (hits), such as new DNA evidence or anonymous tips
- Contacting victims and/or family members with new information
- Following a specific course of action, including obtaining new DNA samples and collecting new evidence
- Building a new case to present to the district attorney
- Utilizing internal/external resources, such as:
- Medical officer/coroner’s office
- Internal or external criminalists or other specialists (fingerprint, firearms, forensic)
- Other detectives within the cold case unit or police department
- Federal agencies, such as the Federal Bureau of Investigation or the U.S. Marshals
- National/state databases, such as the National Center for Analysis of Violent Crimes and DNA databases
Detectives must be able to prioritize their cases and give priority to those in which:
- Witnesses can identify suspects
- Information/evidence can identify suspects
- The initial investigation had witnesses who could not be located or who needed to be re-interviewed
- Preserved evidence can be processed and analyzed through modern technology
Training for Cold Case Investigators
Training prepares investigators to maximize the successful prosecution of cold cases, understand the key elements necessary to operate a cold case homicide squad, and develop strategies for working with the media in high-profile investigations, among others. By providing training in advancements in technology and associated investigative techniques, detectives in cold case units are equipped with the knowledge and skills necessary to successfully investigate and resolve cold cases.
Training for cold case investigators is also often focused on the utilization of the newest technology and resources, including DNA evidence.
As such, these courses are designed to:
- Educate investigators on the basics of forensic biology and its implication when solving cold cases
- Provide a practical foundation in DNA evidence identification
- Educate investigators about the best practices related DNA evidence
- Provide a background on statute of limitations