Police arrested a possible serial killer in Florida Wednesday who was accused of murdering three homeless people. Nathaniel Petgrave, 22, was also homeless and worked as a security guard, according to the Sun-Sentinel.

Petgrave reportedly confessed to the murders and said he used a gun and construction tools to kill the men, Fort Lauderdale Police Chief Rick Maglione said in a press conference. He told authorities he intended to kill five people in total. Serial murders are qualified by the FBI as any between two and 30 killings.

“And this individual did kill three,” Maglione said. “So I guess, by dictionary definition, he would qualify as a serial killer.”

The three victims were identified as Larry Scott, 65, John Jackson, 50, and Derick Westley Tucker, 46. The men were killed between Oct. 21 and Oct. 27. Detectives found a handsaw and a machete allegedly used by Petgrave next to one of the victims’ bodies. Also beside the body was a message written in blood that said “4 STOP WAIT TIME.” Authorities said the number was an apparent reference to his victims, as Petgrave believed he had killed four people.

“To the best of our knowledge and everything we’ve looked at, we don’t believe he targeted these victims for any reason other than their availability,” said Fort Lauderdale Police Sgt. Steve Novak, according to the Miami Herald. “I think the victims that he chose were just available at the time he was out.”

Petgrave was located by detectives in a black pickup truck that was stolen in September. While he confessed to stealing the tools, he reportedly told officers they would never find the gun used in the murders.

Petgrave was being held without bond on three counts of premeditated murder and a charge of attempted premeditated murder. He had not yet entered a plea.