How Many Cold Cases Are Unsolved? Understanding the Numbers Behind the Headlines

The United States has a large unresolved backlog

The National Institute of Justice has cited an estimate of about 250,000 unresolved homicides in the United States. NIJ also noted that more than 100,000 unresolved homicides accumulated during the twenty years ending in 2017.

For perspective, an independent archive containing 1,000 unresolved cases would represent only about 0.4 percent of a 250,000-case estimate. That does not mean the other cases are forgotten by police. It shows how large the national problem is.

Clearance rates have changed over time

NIJ reported that the U.S. homicide clearance rate was about 80 percent in 1965 and around 60 percent in 2017. A clearance rate is not exactly the same thing as a final count of unsolved cases, but it helps show how many investigations remain without a recorded clearance.

Older cases can also be solved years later. That means a case listed as uncleared in one year’s report may not remain that way forever.

Canada and Australia tell the story differently

A Statistics Canada review looked back at homicide records dating to 1961. After older records were updated, about 85 percent of roughly 24,000 homicides in that historical dataset had been solved.

Australia’s latest national homicide report found that 85 percent of homicide incidents in 2024–25 were cleared at the time of reporting. Across Australia’s homicide monitoring program since 1989–90, the report listed 870 incidents, about 9 percent, as still uncleared.

These figures should not simply be added together. They cover different years and use different national systems.

Television shows only a small window into the real problem

Cold-case television often focuses on investigations that have a clear ending. That makes sense for storytelling, but it can give viewers the impression that resolutions happen more often than they really do.

Houston’s Cold Case Unit, for example, still publicly features unresolved homicides dating back to the 1980s. We found no reliable official source for the popular description of Houston as the “unsolved homicide capital” of the 1980s, so we do not use that label as a fact.

The larger point does not need exaggeration. Hundreds of thousands of U.S. homicide cases are estimated to remain unresolved. Every number in that total represents a person.