By Carey Codd

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FORT LAUDERDALE (CBSMiami) – A suspected serial killer, now off the streets of South Florida, left a bloody message next to one of the bodies. He wrote “4 Stop Wait Time” in the blood of his fourth victim Derick Tucker. Police also found a blood-covered handsaw and machete next to the body.

Police say Nathaniel Petgrave had been on a killing spree, targeting homeless men in Fort Lauderdale.

Authorities say Petgrave shot and killed 65-year-old Larry Scott in Lauderhill on Oct. 20, killed 50-year-old John Jackson in Fort Lauderdale on Oct. 21 and killed Derrick Tucker in Fort Lauderdale in Oct. 27.

Nathaniel Petgrave is accused of targeting and killing homeless men in Fort Lauderdale. (Source: Broward Sheriff’s Office)

When detectives questioned Petgrave, they said he told them the number “4” written in blood was because he thought Tucker was his fourth victim.

What he did not know was his unnamed second victim, who was shot in the neck and left for dead, remains hospitalized in critical condition.

The victims were all homeless.

Petgrave, police said, was also homeless and lived in a makeshift shack near State Road 7 and Sunrise Boulevard in Plantation.

He confessed to the murders but did not reveal why he targeted homeless men, according to police

“To the best of our knowledge and everything we’ve looked it we don’t believe he targeted these victims for any reason other than their availability,” said Fort Lauderdale Police Sgt. Steve Novak.

Larry Scott was shot while sleeping at an abandoned gas station in Lauderhill.  The second man, who survived, was shot there the same morning.

The next morning, John Jackson, was shot in the head in the parking lot of a Dixie Food Store two blocks from Fort Lauderdale’s police headquarters. A week later, Tucker was killed while sleeping in a Public Storage unit in Fort Lauderdale.

So how did police catch him?

In a strange twist, Petgrave first encountered police in late September when he was firing a gun for target shooting.

An officer confiscated the weapon, but because Petgrave had a concealed weapons permit the gun was returned a few days later.

A search warrant shows that at some point detectives got a tip that Petgrave might be their killer.

They found Petgrave and he told them he buried the gun where he was camping out.

The gun has not been found, but police from Fort Lauderdale and Lauderhill say the casings from two of the murders are a perfect match.

He got out of jail and police believe he then committed one of the murders.

Apparently, he showed up at the police station to get some of his property back from his arrest for car theft and that’s when detectives arrested him.

“Thank God we got him off our streets. Thank God that we have a safer street tonight, whether you be homeless or not,” said Mayor Jack Seiler.

He is charged with three counts of premeditated murder and is being held in Broward jail without bond.

On Thursday, CBS4 tried to dig deeper into the timeline of Petgrave’s arrest, specifically about whether Petgrave remained under surveillance after he was released from jail on his October 24th arrest and before he allegedly murdered Derick Tucker on Oct. 27.

We asked Fort Lauderdale Police about that and we were told they could not answer our questions because this remains an ongoing investigation.

We also asked why Petgrave was not arrested on the murder charges when he was picked up for auto theft on October 24.

“When we had him here for the auto theft, we had some suspicions but you can’t get probable cause for an arrest based on suspicions,” said Captain Frank Sousa.

Detectives and investigators say they needed to wait to get confirmation from the crime lab that the shell casings from the Lauderhill murder matched the shell casings from the Fort Lauderdale murder.

“We had to wait for ballistic testing that the casings from Lauderhill were an exact match. It’s not like tv, guys,” Sousa said.

Carey Codd