WASHINGTON (WUSA9) -- It's a horrifically violating crime – rape.

After the assault, victims often undergo an invasive, 4-hour exam where a nurse collects DNA evidence from their bodies for a kit that help cops find the rapist. But, hundreds of thousands of those kits sit untested all across the country, letting rapists go free.

Testing that kit for DNA can be a fool-proof way to lock up rapists. So, why wouldn't we do everything we can to get these criminals off the street? As you're about to hear, one victim got angry, and after this story, you might be angry too.

It was 1993 in New York City. College student Natasha Alexenko was 20 years old, and after getting together with co-workers, she had just reached her front door. A man was waiting for her. "I thought for certain that I was going to die," she said. "I was raped at gunpoint, and robbed and sodomized by an unknown assailant, and that completely changed my life."

Shattered, Natasha went to police. Then she waited, un-showered, in order to undergo an invasive, hours-long examination of her entire body so a nurse could collect DNA evidence for what's commonly called a rape kit.

"It took about 4 hours to complete, but I knew it was so necessary to aid law enforcement in any way I could and certainly to prevent this man from hurting other people," Alexenko said.

Nine years passed. Natasha's rapist was still not arrested. Then, she found out why. Turns out, the one thing that could help catch him was sitting on a shelf.

"It almost felt like a re-victimization finding out that the kit wasn't tested," she said.

But it wasn't just Natasha's kit. Right now, it's estimated that 400,000 rape kits across the country are sitting on shelves untested. The primary reason? Cost.

"A rape kit costs between $500 and $1,500 to process," Alexenko explains. "When I think about my kit not being tested and I think about Victor Rondon, the man that raped me, I think what that cost taxpayers, what that cost law enforcement, while we didn't test the kit. I'm sure that that cost a lot more than $1,500."

That's because while Natasha's kit just sat, her rapist was out on a 9-year, one-man crime spree.

Natasha tells her story so she can help others. She founded her non-profit, Natasha's Justice Project, in 2011 to raise money and awareness with the hopes of getting every untested kit in the country tested. And her persistence is paying off. WUSA9 was there at Bode Labs in Lorton, Va., as the first 100 backlogged rape kits arrived for testing – a direct result of her hard work.

Natasha thanks Alameda County, Cal. District Attorney Nancy O'Malley for partnering with her to get this done. O'Malley is trying to create a blueprint for other jurisdictions.

"In my county, which has 1.6 million people, we have identified about 2,000 kits that were sitting in the property room of police departments," O'Malley said. "[They] never even got to the crime lab."

There are still hundreds of thousands of kits to go. But Anne Arundel County Executive Laura Neuman knows first hand how even one break can dole out justice exponentially.

"This is a very personal issue for me though, my rape kit sat on the shelf for years, and it was ultimately destroyed," Neuman said.

At 18-years old, Neuman was raped at gunpoint in her bedroom by an intruder. The crime went unsolved for 19 years.

Then, Neuman insisted police reopen the case. Three days later, fingerprints led them to her rapist. Neuman learned if her rape kit had been tested right away, countless women could have been saved from heartache.

"They got a match on 12 more cases," Neuman said. "Those cases would have never been solved had I not pursued getting my case reopened after 19 years."

That's a dozen more women who are free from wondering if their rapist could strike again. It's a feeling Natasha says you can't put a price on. This is how she describes the day her rapist was sent to jail: "It was a day I will never forget. I will never forget how I felt. I think I felt safe for the first time."

If you're wondering how our area figures into that backlog, as of April 24, 2014, 85 kits remain untested in D.C. In Virginia, 117 kits wait for testing, as of April 29, 2014. And in Maryland, none of the agencies we called reported a backlog.

President Obama recently asked for $35 million in his 2015 budget to end the backlog. Congress still needs to approve the spending.

If you would like to help, visit Natasha's Justice Project.