DETROIT -- A second backlog of more than 500 untested Detroit rape kits accumulated in the years after the stunning discovery of over 11,000 unprocessed evidence packages in 2009, according to prosecutors.

At least one sexual assault in 2011 might have been prevented, had Detroit police straightened out the process of testing rape kits within the first few years after the first backlog came to light.

But the problem persisted, and a suspected serial rapist whose DNA was collected in a 2010 rape kit wasn't arrested until January, nearly seven years later, and after he'd allegedly attacked another victim in 2011.

The accumulation of the second batch of untested kits was never publicly announced.

Even after a public outcry and outside intervention when 11,341 untested rape kits were discovered in a Detroit police warehouse in 2009, the second backlog of hundreds more kits sat untested for years, according to prosecutors.

Based on new data obtained by MLive from the Wayne County Prosecutor's Office, at least 555 rape kits collected by Detroit police after 2009 continued to linger for unknown reasons before being sent to an out-of-state DNA lab for testing in 2015.

Out-of-state labs have been contracted in the years since the 2009 discovery to test the backlogged kits, but fresh kits are supposed to be sent to a Michigan State Police crime lab under the current procedure.

And a state law enacted in 2014 requires that police send rape kits for testing within 14 days of receiving them.

Wayne County Assistant Prosecutor Maria Miller said out-of-state laboratory workers, while testing pre-2009 kits, found 555 rape more packages that were collected by Detroit police in 2010 and 2011, and sent for testing in 2015.

Anthony Thornton

The issue of rape kits continuing to go untested after 2009 wasn't announced by the Detroit Police Department, but was exposed -- possibly by accident -- by the Fair Michigan Justice Project, a partnership between the nonprofit LGBTQ advocacy group Fair Michigan and Wayne County Prosecutor Kym Worthy's office.

On Jan. 25, the Fair Michigan Justice Project issued a press release announcing the arrest of 46-year-old Anthony Thornton, a suspected serial rapist accused of participating in the gang rape of a homeless, lesbian woman in April 2010; and the kidnapping and rape of another Detroit woman on March 8, 2011.

Thornton is scheduled to stand trial May 15.

It's unknown whether there were more victims, but Thornton's DNA has been on file in the national Combined DNA Index System database, which is accessible to prosecutors and law enforcement, since 2006.

Had the rape kit submitted to Detroit police by the 2010 victim been tested in a timely manner, authorities might have been led to Thornton before the second rape occurred.

"How that happened or why that happened, you would have to ask the Detroit Police Department," Worthy told MLive.

Detroit Police Media Relations Director Michael Woody said that under current testing procedures, rape kits are "immediately sent to the (Michigan State Police lab) for testing."

The 555 post-2009 kits that inexplicably sat for years weren't sent directly to a Michigan crime lab, but instead, directly to out-of-state labs specifically handling the 2009 backlog.

"No," Woody said when asked if anyone has been or would be punished over the post-2009 backlog.

"The fact they were not being tested was a result of many different factors. It was not a matter of officers not willing or intentionally neglecting their duty."

Woody did not elaborate on the factors that led to the backlog and didn't respond to several requests for further comment.

The new backlog

Of the 555 rape kits sent for testing in 2015, 135 yielded DNA profiles that matched samples already on file in the national database, according to the Wayne County Prosecutor's Office.

Another 420 kits had "negative test results," according to the prosecutor's office, meaning there wasn't adequate evidence to create a DNA profile.

Of the 135 cases with DNA profiles:

While Detroit police failed to immediately test rape kits for decades, it's unlikely it will happen again, said Kimberly Hurst, the executive director of Wayne County SAFE.

Wayne County SAFE is a nonprofit that administers all of the rape kits, also called sexual assault evidence kits, throughout the county before turning them over to law enforcement agencies for investigation.

Under a Michigan law passed in 2014, once a rape kit collection is conducted, police have 14 days to collect it and another 14 days to send it to the proper lab for analysis.

Hurst said Detroit police for the last two years have been part of a pilot program with UPS that allows her organization to track every rape kit requiring forensic testing and ensure the department is in compliance.

She said the group was "surprised and frustrated" when the 2009 backlog was discovered, and that procedures now in place and the culture among police in regard to handling rape cases "is much better."

A 551-page report commissioned by National Institute of Justice and released by Michigan State University in April 2015 looking at the 2009 Detroit rape kit debacle found that staff cuts and budget restraints led to investigators "cutting corners" and exerting "minimal effort" to solve sex crimes.

Often, that meant closing cases and shelving rape kits.

Police "expressed negative, victim-blaming beliefs about sexual assault victims," the report found. "Rape survivors were often assumed to be prostitutes and therefore what had happened to them was considered their own fault.

Full report

"Adolescents were assumed to be lying, trying to avoid getting into trouble by concocting a false story about being raped. Police said those who had been assaulted by friends and acquaintances "got what they got" because they chose to associate with the perpetrator."

The report found that "case after case" was dubbed "a deal gone bad" or "not really a rape" and closed.

It's not clear whether some of the same factors contributed to the 550-plus kit backlog discovered in 2015.

So far, nearly $17 million has been raised through government grants and private donations to test and investigate the pre-2009 rape kits, as well as to create a national testing protocol.

There are currently fewer than 1,000 remaining 2009 backlog kits to test, according to Margaret Tallet, chief community engagement officer for Enough SAID, the organization coordinating the effort.

Worthy said earlier this month that testing of the pre-2009 kits resulted in 78 convictions and the identification of 784 suspected serial rapists. Over 50 of the 784 are believed to have committed sex assaults 10 to 15 times each.

Worthy said the backlog problem isn't isolated to the Detroit Police Department and is "certainly a national issue." She estimates a national backlog near 400,000.

The Detroit police rape kit issue prompted other agencies across the state and nation to address backlog problems of their own.

Attorney Bill Schuette in January 2016 revealed 1,819 untested kits were located in police departments across Michigan's 82 counties, including 261 at the Flint Police Department; 261 at the Battle Creek Police Department; and 239 at the Grand Rapids Police Department.

This article has been corrected. The number of serial rapists believed to have committed 10 or more offenses was initially reported incorrectly.