A former Tennessee Bureau of Investigation special agent fired last year for mishandling a blood alcohol sample only botched results one time out of the couple thousand samples he tested, the state agency said.
"We have not had any evidence of any other switched samples or anything to cause concern," said Josh DeVine, TBI spokesman.
The state's law enforcement agency recently received the last batch of results from all of the drug and blood cases that former Special Agent Kyle Bayer had tested.
TBI sent all of those samples -- which included 323 cases in Hamilton County -- to AIT Laboratories, a private lab in Indianapolis, Ind., for re-testing to ensure there were no wrongful convictions.
Re-testing the 2,827 samples cost the state $98,945, DeVine said.
Bayer was fired in October after an internal investigation showed that he had switched two blood alcohol samples in a vehicular homicide case in Hamilton County.
The error surfaced after Chattanooga defense attorney Jerry Summers sent Dale Edward Ferrell's blood sample to a private lab which came back with .01 level, lower than the .24 blood alcohol content that Bayer claimed when he tested the sample.
Summers, who is representing 25 clients, is having some clients' results tested a third time. Among the clients Summers is representing is Chattanooga Police Officer Christian Lorenzen, who was arrested for DUI in April 2013. Lorenzen has since been arrested again for DUI in March.
"There's some difference in some of them," Summers said. "We've asked for re-testing in some of the samples. Some of those cases are high blood alcohol levels. Some of them are lower."
After Bayer's error, TBI added another step in the lab process when testing samples, DeVine said.
"All batches of cases -- both drug and alcohol testing -- are checked by a second person to make sure the correct sample is in the correct position," he said. "We've added a layer of accountability internally."
Contact staff writer Beth Burger at bburger@times freepress.com or 423-757-6406. Follow her on Twitter at twitter.com/abburger.