ROANOKE, Va. -

WDBJ7 is uncovering that law enforcement agencies across Virginia, including here in our area, are not following state recommendations when it comes to questioning eyewitnesses.

A recent study done by a University of Virginia law professor shows about 90% of the police agencies are not playing by the rules.

UVA Law Professor Brandon Garrett told WDBJ 7 that the city of Roanoke has some of the best policies, but not every local agency is following suit.

Eyewitness testimony can make or break a case and that's why Roanoke City Police Chief Chris Perkins said he holds his agency to the highest standards.

"There's nothing worse than having the wrong person convicted for a crime and so we make painstaking efforts to prevent that and it goes on all across the state," said Perkins.

A recent study conducted by Garrett found that most law enforcement agencies are not following in Perkins footsteps.

"I saw policies that didn't even have written down instructions for what to tell the eyewitness, nothing careful about making sure you don't give the eye witness feedback, so there's all sorts of problems," said Garrett.

He found that 90% of Virginia police agencies don't follow proper protocol when presenting suspect lineups to eyewitnesses.

"We know a lot about how to do a line ups right,” Garrett said. “The most important thing is to have the one running the lineup be blind, be that they don't know who the suspect is."

Garrett and Perkins agreed that knowing who the suspect is can lead to wrongful convictions, but Perkins said there's more to be said about that 90% finding.

"I don't know it's by any fault of their own,” said Perkins. “I think that it boils down to a lot of factors that go into that. It may be the size of their agency, the size of their community, the needs of the community. It may be whether they have accreditation or not."

Garrett said police departments often had no written policies on conducting lineups or eyewitness identification, but in 2011, a new state model was adopted in response to a series of DNA exonerations caused by eyewitness misidentifications.

Garrett wrote the following about his case study results:

“Of the 201 law enforcement agencies that responded, 144 supplied eyewitness identification policies. Troubling findings included that in total, only 29% required blind lineup procedures and only 40% made blind lineup procedures available even as an option. Only 6% adopted the revised model policy. The results suggest that institutional inertia, and not policy choices, explain the slow pace of adoption of best practices. As a result, dissemination of best practices by state policymakers may not be enough, and stronger regulatory measures may be required to safeguard the accuracy of criminal investigations.”

Garrett could not release the details of his results because he promised confidentiality to the agencies.

WDBJ 7 called other local agencies to see which ones have written policies and which ones are up to date with standards.

Martinsville, Salem, Vinton, Pulaski, Lynchburg, Danville and city of Roanoke all have written policies.

The Salem Police Department told WDBJ 7 that the current policy does not meet the standards set forth by the Virginia Department of Criminal Justice Services. The department is currently in the process of tweaking it and hopes to have a new one by next week.

The Christiansburg Police Department is the only agency that does not currently have a written policy. They said they are currently working on one.