The initial DNA test results for the body believed to be suspected Kentucky highway shooter Joseph Couch came back inconclusive on Thursday.

Kentucky State Chief Medical Examiner Dr. William Ralston said the autopsy included a soft tissue DNA test that failed to identify whether the body was that of Couch. Further testing of samples taken from bone will be conducted on Friday and could take as long as 48 hours to complete.

The autopsy did, however, determine a cause of death, Ralston said.

“At this time, we are able to confirm that the autopsy revealed the cause of death to be a wound consistent with a self-inflicted gunshot to the head,” he said Thursday afternoon. “In addition, we are performing a toxicology test to verify if any drugs were present.”

Joseph Couch was named a suspect in the apparently random Sept. 7 mass shooting on I-75 in London, Ky.

Roughly 30 minutes before the shooting, Couch reportedly texted someone believed to be his ex-wife, saying he was “going to kill a lot of people. Well, try at least.” He also indicated he planned to turn the gun on himself afterward.

A body was found in the woods near the site of the shooting on Wednesday by a pair of YouTube live streamers who were following a circling vulture.