Cold cases have always been a point of interest for the public due to the unknown factors surrounding a case. A cold case is defined as a homicide or a felony sexual offense that remains unsolved for one year or more after being reported to a law enforcement agency and that has no viable and unexplored investigatory leads. According to the Cold Case Project, there are approximately 426 cold cases in Arizona. Of those, 418 are from Maricopa County.

Earlier this year, the County Attorney's Office received a grant from the Department of Justice through the Bureau of Justice Assistance's Prosecuting Cold Cases Using DNA Program. This Program is designed to help prosecutors by providing funding to support agencies in resolving violent crimes and cold cases. Funds received by MCAO will be used to pay for additional DNA testing, create a countywide cold case database, hire a data analyst, and ultimately be a multiplier of resources for prosecutors and law enforcement agencies in the Valley. Currently, cold case homicide prosecutions are handled by two prosecutors who are experts in DNA evidence, three investigators who have over 63 combined years of experience, and a paralegal.

Solving and Prosecuting Cold Cases

So, how does a cold case investigation get started? A cold case is reopened when there is new information, new technology that may create new leads, or through a public inquiry. MCAO detectives become involved in a cold case investigation when a law enforcement agency invites them. Unlike an active criminal investigation, a cold case investigation is much more challenging to solve due to several factors. The first is the evidence: detectives will locate and verify that the evidence still in custody hasn't been lost or destroyed. Next, detectives review the evidence, including reports, photographs, lab analysis, and physical evidence when the evidence is found. If DNA evidence is available, it will be sent for additional testing. Once a profile is created, it will be submitted to the national Combined DNA Index System (CODIS) database for a match. The second factor is subjects: detectives have to locate everyone involved in the case, including witnesses, medical examiners, or initial investigators. Often, these subjects may not be alive anymore or may not remember the case.

Much like solving a cold case, prosecuting one is no easy task, even if the case has been solved. For example, if DNA is used to solve a case, prosecutors must track down the person who collected it or someone that can verify the person who collected it for that evidence to be admissible in court. Other issues involve the chain of custody or the number of people who touched the evidence, which is challenging to find a full report in old cases.

Even through these barriers, MCAO detectives and prosecutors have successfully helped solve and prosecute several cold cases in Maricopa County. Victims and survivors are impacted differently when a cold case is solved and prosecuted. For some, it brings them closure and healing. For others, it's difficult to relive the trauma so many years later. Cold cases are never forgotten by victims, survivors, their families, and the allied professionals who work to solve them. For the prosecutors and detectives in our office, it makes a difference to bring justice for all by holding offenders accountable for these violent crimes