MEMPHIS, Tenn. (AP) — Memphis police are investigating whether a suspect charged with killing a homeless man has targeted other homeless people in the city, a spokesperson said.

Kurt Loucks, 41, was charged Friday with first-degree murder in the fatal shooting of Shaun Rhea.

Loucks attacked Rhea early Friday morning in downtown Memphis, police said in an affidavit. A security guard at a nearby hotel said he saw Loucks use pepper spray against Rhea while Loucks was armed with a knife, police said.

Loucks went into his apartment but returned and shot at Rhea with a rifle, according to police, citing the security guard’s statement. Rhea, who was unarmed, died at a hospital, police said.

Loucks is being held without bond. A preliminary hearing has been scheduled for July 9.

Blake Ballin, Loucks’ lawyer, said he was looking into whether Loucks was acting in self-defense during two confrontations with Rhea. Loucks was honorably discharged from the U.S. Army because he was disabled due to post-traumatic stress disorder, Ballin said.

The security guard told police that there had been several incidents where Loucks had attacked homeless people, the police affidavit said. Police are investigating whether Loucks has targeted homeless people in the past, Memphis police spokesman Christopher Williams said in an email.