News Release

Rape kit data yield major implications for sexual assault investigations

New data challenges conventional wisdom about rape among scholars, advocates, police and prosecutors

Peer-Reviewed Publication

Case Western Reserve University

Rachel Lovell, Case Western Reserve University

image: Rachel Lovell, Ph.D., a Senior Research Associate with the Begun Center for Violence Prevention Research and Education at Case Western Reserve University's Jack, Joseph, and Morton Mandel School of Applied Social Sciences view more 

Credit: Case Western Reserve University

The testing of nearly 5,000 forgotten and backlogged rape kits in and near Cleveland has led to investigations, indictments, prosecutions -- and, already more than 250 convictions.

But besides bringing justice to long-ignored victims and taking scores of violent offenders off the streets, the efforts of the Cuyahoga County Sexual Assault Kit Task Force are also helping to change how law enforcement agencies and the academic community view and prosecute rape.

That's because the Task Force has partnered with researchers from the Begun Center for Violence Prevention Research and Education at Case Western Reserve University's Jack, Joseph and Morton Mandel School of Applied Social Sciences, and has given unprecedented access to information on hundreds of sexual assaults committed between 1993 and 2010.

The research team discovered serial rapists are far more common than previous research suggested--a finding that could change how sexual assaults, including so-called acquaintance rapes, are investigated. They are also learning more about how rapists operate and their victims.

"By working together, we can help change the way sexual assaults are investigated and how the system and society view sexual assaults, victims, and offenders," said Daniel J. Flannery, the Dr. Semi J. and Ruth W. Begun Professor at the Mandel School, director of the Begun Center, and co-lead researcher of the Cuyahoga County Sexual Assault Kit Pilot Research Project.

"We have an historical opportunity and obligation to make a difference," he said.

"These rape kits have been the greatest gold mine of information and leads for law enforcement that I have seen in my four-decade career," said Cuyahoga County Prosecutor Timothy J. McGinty. "We are going to end up prosecuting a thousand criminals, and that will make our county significantly safer. But we also want to learn from mistakes that created this backlog and never allow them to be repeated."

"The thousand or more cases we expect to solve will help us understand the behavior of these career criminals so that police can more effectively and promptly investigate and prosecute rapes. This task force will prevent new victims from being attacked because these criminals will be in prison," McGinty added.

Among the research team's early findings, available in a series of briefs now online (

  • Serial rapists are far more common than previous studies had suggested. Of the 243 sexual assaults studied, 51 percent were tied to serial offenders, who generally had more extensive and violent criminal histories than one-time sexual offenders.

    "Our findings suggest it is very likely that a sexual offender has either previously sexually assaulted or will offend again in the future," said Rachel Lovell, a senior research associate at the Begun Center and co-leader of the Cuyahoga County Sexual Assault Kit Pilot Research Project. "Investigating each sexual assault as possibly perpetrated by a serial offender has the potential to reduce the number of sexual assaults if investigations focus more on the offender than on single incidents."

  • Rapists have long criminal histories that often began before their first documented sexual assault and continued after it.

    An overwhelming majority of both serial and one-time sexual offenders had felony-level criminal histories: 74 percent of all serial rapists had at least one prior felony arrest and 95 percent of them had at least one subsequent felony arrest. Among one-time sexual assault offenders, the figures were 51 percent and 78 percent.

    Among the serial sex offenders, 26 percent had a prior arrest for sexual assault and 60 percent had a subsequent arrest for sexual assault (not related to the sexual assault identified in the SAK Initiative).

    "These are one-man crime waves," said Prosecutor McGinty. "And now that we realize this, we cannot allow these kits to sit on shelves untested in the future. They hold the keys to identifying and convicting dangerous criminals."

  • Serial and one-time rape suspects exhibited different behaviors during their crimes.

For example, sexual assaults committed by serial offenders more frequently involved kidnapping victims and then verbally and physically threatening them, often with weapons. And yet sexual assaults committed by serial offenders less frequently involved restraining victims and injuring them in order to complete the attack. One-time offenders were actually more likely to punch, slap, hold down or restrain a victim.

Serial offenders were more likely to commit sexual assault outdoors, in a vehicle, or a garage while a one-time offender was more likely to attack in his own house, or the house of the victim or a third party. Serial sexual offenders tend to attack in the same type of location: 58 percent of serial offenders commit all of their crimes in the same type of setting.

One-time offenders are more likely than serial offenders to commit sexual assaults with others, such as participating in gang rapes.

  • Serial offenders were more frequently strangers to their victims compared to one-time offenders.

    Half the serial offenders assaulted only strangers, but fully a third of them had a mix of known and unknown individuals among their victims. This underscores the need to thoroughly investigate acquaintance rapes, because of the possibility those offenders have or will engage in assaults against strangers, too.

Also of note: Even in cases of assaults by strangers, victims frequently provided some kind of identifying information to police, such as a partial name, a nickname or a license plate.

  • Most victims, even in the backlog, initially cooperated with police. The drop-off came after the first reporting encounter between investigators and victims: 69 percent did not respond to further attempts to be contacted by police.

Victims in the cases studied -- all but three of them female--ranged in age from two to 70, with an average age of 26. Nearly 70 percent were African American, a reflection of the neighborhoods where the incidents documented in the backlogged rape kits took place.

In 2013, Prosecutor McGinty organized the multi-agency Task Force to investigate DNA evidence generated by Attorney General Mike DeWine's Sexual Assault Kit Testing Initiative. A year later, McGinty approached the Begun Center to mine data accumulated through the testing, investigation and prosecution of nearly 5,000 rape kits collected but not tested for DNA between 1993 and 2010.

Researchers coded police and investigative reports, DNA lab reports, and criminal histories of victims and defendants identified through DNA testing -- histories that in many cases include lengthy lists of arrests, convictions and violent incidents.

"We can start to say we have a better picture of who victims are and who offenders are," said Lovell.

"Also, we know more about how offenders rape. How cases moved through the process--or failed to move to prosecution. How can we do a better job of holding offenders accountable. We have data on a larger and more diverse group of rapists, which allows us a better understanding of what kind of rapists commit certain kinds of crimes -- and how this information can aid an investigation," Lovell added.

Prosecutor McGinty said the Task Force has been "phenomenally successful." To date, 462 defendants responsible for more than 500 sexual assaults have been indicted. Prosecutors have won convictions in 92 percent of completed cases, with an average sentence of 10 years. A team of investigators, advocates and prosecutors is currently working on more than 2,700 cases.

"Law enforcement greatly underestimated the positive results that would come out of investigating these rape kits," Prosecutor McGinty said. "We are identifying, prosecuting and punishing some of the most dangerous violent repeat offenders in our communities. The research now coming out of the Begun Center is reinforcing the importance of this work, not only in Cuyahoga County, but nationally."

As researchers move forward with this project, they hope to explore additional topics, including a deeper understanding of different types of serial and one-time offenders, the characteristics of victims that significantly impact an investigation and prosecution of a rape allegation, and how communication between police and victim affects continued victim cooperation.

Additional funding to expand the Begun Center's research came last fall as part of $2 million Department of Justice grant to the Cuyahoga County Prosecutor's Office to support the work of the Sexual Assault Kit Task Force.

"The experience of collecting a rape kit is invasive and especially so right after a victim has been traumatically assaulted. These victims did what they have been asked to do to preserve evidence--but that evidence just sat, untested," said Lovell. "The new processes we hope will emerge from our effort will better honor victims."


In addition to the Cuyahoga County Prosecutor's Office, the Task Force includes the Ohio Bureau of Criminal Investigation, the Cleveland Division of Police Sex Crimes Unit, the Cuyahoga County Sheriff's Department and Cleveland Rape Crisis Center.

Additional researchers on the project from the Begun Center include: Fredrick Butcher, a research associate on the project; and Tiffany Walker and Laura Overman, both research assistants.

Read the four research briefs at:

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