A man who suffered a single gunshot wound to the abdomen Monday has been released from the hospital, said Austin Police Chief Brian Krueger on Wednesday.

Krueger added that detectives continue their investigation as to how it came that the 28-year-old man was injured.

“We are still working on developing suspects,” Krueger said on Wednesday. He offered no other details, due to the ongoing nature of the investigation.

Officers responded to a call just after 11 p.m. at Mayo Clinic Health System in Austin after the man was dropped off at the facility by someone driving a silver, four-door vehicle, according to hospital staff. The man was able to walk into the hospital.

By the time police arrived, the man was intubated and could not give any information. He was then transported to Mayo Clinic Hospital, Saint Marys Campus-Rochester emergency room.