In a refrigerator in the coroner's office in Marion County, Ind., rows of vials await testing. They contain blood, urine and vitreous, the fluid collected from inside a human eye.
In overdose cases, the fluids may contain clues for investigators.
"We send that off to a toxicology lab to be tested for what we call drugs of abuse," said Alfie Ballew, deputy coroner. The results often include drugs such as cocaine, heroin, fentanyl or prescription pharmaceuticals.