Here's What Really Constitutes A Cold Case

The prevalence of police-focused dramas and prestige TV shows as well as the huge current interest in true crime across a range of media means that the average American tends to know more technical and colloquial terms and phrases related to police than they do possibly any other line of work outside of their own. A 'cold case,' for example, is seemingly understood by almost everyone, as a term to denote when detectives investigating a crime reach a dead end, are unable to gather required evidence or identify credible witnesses, and the investigation grinds to a halt, leaving justice wanting for years on end.

Cold cases are also of special interest to news audiences and true crime enthusiasts — the slow drip of potential new information is a definite dopamine-infused draw, while the suspense built either in the course of one report or over many months and years concerning whether a viable suspect might eventually be arrested and charged means cold cases present stories that are tantalizingly unresolved. They also provide an outlet for would-be sleuths to indulge their own Sherlock Holmes-esque deduction skills from the comfort of their own armchairs and benignly dream of beating the pros in finding the killer, as Time notes.

But though we may think we know exactly what a cold case is, the term itself is ambiguous; some cases may be years old but still active, while others may stall instantly. So what do real police investigators mean when they use the term 'cold case,' and how do cold case task forces go about solving them?

Though cold cases that become the stuff of documentary series and podcasts are typically murders, the crimes involved don't have to be for a case to technically be considered 'cold.' According to Law Insider, a cold case can involve any felony — a definition that crucially excludes misdemeanors — for which the statute of limitations has not yet passed.

Just as American laws vary somewhat from state to state, the rules and definitions of individual police forces are also different in various states across the country. However, Law Insider states that the length of time that needs to have passed before an active case can be described as 'cold' is one calendar year, a period of time that is also echoed by several Departments of Justice, such as the one in New Hampshire. Meanwhile, the website of the police department in Houston, Texas defines a cold case as one that remains unsolved after three full years.

Per the same source, a case is classed as cold when the investigators assigned to the case are believed to have chased up all "probative investigative leads" concerning who may have committed the crime or crimes in question, but have been unable to charge a suspect. New Hampshire makes the technical point that not all cases unsolved after a certain period are considered cold, however, as suspects already imprisoned or on trial for other crimes may cause an investigation to be suspended, or there may be other technical reasons not to file charges.

Though the moment a case is declared 'cold' is typically when all hope in seeking a just resolution appears to have been lost, countless people are dedicated to reviving cold cases, with police forces in many states operating their own 'cold case units' to revisit past suspected crimes. Many, like that in New Hampshire, focus exclusively on cold homicide cases.

As noted by the Houston, Texas police department, cases may be reopened upon review or when new technological advances pave the way for new investigations into how a crime might have been committed. Similarly, a case may be reopened by a cold case unit following the receipt of fresh information from a member of the public.

Similarly, many private individuals also become involved in attempting to solve cold cases, either as professional investigators hired on behalf of families and friends of the victims of crime or the victims themselves, or as amateurs who for one reason or another have a special interest in having the case solved and finally bringing the criminals involved to justice.