DETROIT (WWJ) – Testing rape cases remains a thorn in Wayne County Prosecutor Kym Worthy’s side. This week she took her pledge to have 11,000 rape kits tested to the national stage.

Rape kits are done by hospitals to collect often the most important evidence used to convict in a rape case: DNA.

Speaking on NBC’s Rock Center Friday Worthy says the kits have quote “fallen through the cracks.”

Worthy was asked by the primetime show about a Detroit police internal investigation into the problem.

“Their reasons were just made up reasons as to why there should be no investigation,” said Worthy.

NBC News says Detroit police randomly reviewed 36 cases in 2009 and determined “justifiable reasons” the rape kits were not tested…including witnesses unwilling to testify and suspects pleading guilty to lesser charges.

Prosecutor Worthy goes so far as to say the city’s public safety agency lied about why these case were never brought to her attention:

“So we have 21 serial rapists out of roughly 600 … kits that have been tested … almost three times more than we would expect,” she said.

DPD told Rock Center those reasons include victims who refused to prosecute or were uncooperative and assailants who pleaded guilty to lesser charges.

If you want to see those rape kits tested, you can donate to the prosecutor’s office Rape Kit Initiative, you can learn more about the project – HERE.