A recent investigation revealed that in nearly 400 cases, police departments across the country have thrown away rape kits.

Rape kits are the pieces of evidence collected by a nurse after a rape is reported. They take nearly four hours to compile and include physical tests and questions. They often provide crucial evidence in rape cases, but many consider the tests highly invasive — making the destruction of the kits even more galling to some survivors.

These were in even in the cases when the statute of limitations had not expired, or there was no time limit to prosecute. This practice happened as recently as 2016.

CNN, who reported the investigation, spoke to Kym Worthy, a prosecutor in Wayne County, Michigan. “Each one of these kits represents a victim,” she told them. “What you are doing when you destroy a rape kit is destroying the chance that they are ever going to see justice.”

In addition to cold cases, preserving and testing rape kits has the potential to help solve future crimes. Detectives investigating a rape, for example, may be able to link a suspect’s DNA to an earlier sexual assault in which DNA was uploaded to CODIS and establish a pattern of criminal behavior — something not uncommon among rapists and child molesters.

And the issue doesn’t only affect survivors. CNN reported on the case of Keith Harward, who spent 33 years in a Virginia prison after being wrongfully convicted of rape and murder. Because a rape kit was kept and later tested, Harward went free.

We’re talking to the reporters behind the investigation to learn how the system broke down.

If you’re a survivor of sexual assault, Rape, Abuse & Incest National Network (RAINN)’s survivor helpline is 800-656-4673. The organization will send callers to nearby organizations for further resources and support