PINE TWP, Mercer County — A suspected marijuana dealer died of a broken neck during an altercation with two assailants in what state police said was a weekend robbery gone bad.

Police on Monday arrested the Grove City men in the death of 60-year-old Michael Anthony Johns Sr., who died outside his mobile home in Pine Township near the Mercer-Butler County line.

Ryan P. Bowers, 23, and Patrick S. McCamey, 39, are both being held in the Mercer County Jail without bail on charges of second- and third-degree murder and robbery.

Both defendants confessed to killing Johns after they went there to rob him of drugs and money, police said.

Investigators suspect Bowers and McCamey attacked the victim, choking him so hard that his neck broke. An autopsy ruled Johns died of strangulation.

A neighbor Sunday afternoon found the body outside the victim’s trailer on Irishtown Road near Route 58 and notified authorities.

Investigators said it appeared Johns had suffered trauma about his neck. Nearby was a badly damaged knife and a blood trail leading away from the home.

Police initially could not explain the blood because Johns had no bleeding injuries. They also did not immediately know the knife’s owner.

Later, investigators learned the blood was from the suspects. The knife belonged to Johns.

“The victim at some point during the altercation managed to pull his knife and stab both suspects in the legs,” said Lt. Eric Hermick of the Butler barracks.

The knife’s handle and blade were broken off during the life-or-death struggle.

Police said Bowers and McCamey eventually got the better of Johns.

The injured defendants fled, leaving behind a trail of blood, and headed to their alleged getaway car parked nearby close to an auto dealership.

They called a family member and asked for help to get them to a hospital. The relative obliged and drove them to Allegheny General Hospital in Pittsburgh.

Both men were treated and released. The relative subsequently notified police just before noon Monday.

Police, in turn, took the defendants into custody. They were interviewed and admitted their roles in Johns’ death.

The suspects acknowledged they had gone to his home “to do a home invasion,” Hermick said, possibly under the guise of buying marijuana.

Police described the victim as a drug dealer.

“He dealt marijuana to an older crowd, usually,” Hermick said.

But before the defendants got into his home, Johns, dressed in underwear and a T-shirt, confronted them in his yard about 6 a.m., police said.

Both defendants have criminal records in Butler and Mercer counties.

Bowers was convicted of a 2012 home invasion robbery during which he brandished a gun and stole nearly $300 from a couple in Slippery Rock Township, Butler County.

Court records showed he was sentenced to 2 to 5 years in state prison. He was given credit for 166 days time served and subsequently released earlier this year.

Among Bowers’ other convictions are possession of marijuana, receiving stolen property and access device fraud.

McCamey’s records showed convictions for simple assault, drunken driving, possession of drug paraphernalia and false reports to police.