Montana's crime lab is tracking a possible backlog in evidence used to prosecute rape cases. The crime lab estimates there are roughly around 1,650 untested kits statewide.

NBC Montana reports an administrator with the Forensic Science Division says state officials wanted to know how many rape kits, if any, were backlogged in Montana.

The division started sending out surveys to law enforcement agencies across the state. The idea is to try to gauge how many rape kits are stored in local evidence rooms.

A rape kit is a small box filled with envelopes, swabs, tape -- everything needed to gather evidence from a rape victim to prosecute an attacker.

Inside each one there is a story of an attack.

"When properly stored like it is in these law enforcement vaults, the DNA is stable for decades," said Forensic Science Division administrator Phil Kinsey.

His team found one in Montana from 1995. “A kit that was collected back in 1995, the evidence should still be viable," said Kinsey.

Kinsey said rape kits are not stored at the state crime lab, but with local law enforcement in their evidence rooms.

The kits are brought to the lab if police, prosecutors and the victim decide to pursue a case.

"There might be a number of reasons why those kits haven't been forwarded, whether or not the victim wants to move forward and then depending on the investigation," said Kinsey.

Kinsey says the crime lab processes about 150 to 200 rape kits per year. Now his division is trying to be proactive and help law enforcement by processing more.

Each one is pretty expensive. "A real rough estimate is $1,000 to $1,500 per case."

That's why they will be looking to grants from the National Institute of Justice so they can help out more.

"One thing that you don't want to have happen is to have a large influx of cases that all of a sudden get brought to the laboratory. Now, all of a sudden, we're trying to get out from underneath, now we are trying to process a lot more evidence than we are currently capable of," said Kinsey.

The survey process is not over yet. Kinsey says they are still waiting to hear back from some local law enforcement agencies.

He's hoping it will be completed within a month or two so they can plan what they need to do next.

A rape kit usually takes about three months to process.  The kits can be submitted to private companies for processing as well.