BROWARD COUNTY, Fla. (WFLA) – Broward County detectives say a suspected serial killer used his victim’s blood to send an ominous message, NBC Miami reports.

Nathaniel Petgrave, 22, went on a killing spree targeting homeless people in the area, police say.

He allegedly shot two homeless men in their sleep at a gas station on October 20. One of the men, 65-year-old Larry Scott died at the scene. The other was left in critical condition.

Police also linked him to the October 21 death of 50-year-old John Jackson who was shot in the back of the head while he was working on his car outside of a grocery store.

Six days later, police said Petgrave broke into a storage unit, stole a handsaw and machete and killed another homeless man, 46-year-old Derrick Tucker. Tucker had sustained multiple sharp force and blunt force injuries, police said.

Police said the items were left next to Tucker’s body, covered in blood, and written next to his body in blood was the number “4” and the words “Stop Wait Time.”

Petgrave was arrested last month for operating a stolen vehicle. Police said he confessed to the crimes when he came to the station to pick up his belongings and admitted he wrote the number in blood because he thought Tucker was his fourth victim.STORIES OTHERS ARE CLICKING ON: