ARLINGTON — Witnesses told police that Elliot Carbajal was screaming for help and pleading for someone to call police before he was strangled to death in downtown Arlington.

Prosecutors on Thursday charged Robert L. Carlson, 40, with second-degree murder. The 280-pound man is accused of sitting on Carbajal’s chest and choking him to death Dec. 11 during an early morning dispute.

Carbajal, 40, was found unconscious and rushed to Harborview Medical Center in Seattle. He was kept on life support until Dec. 16. The Snohomish County medical examiner determined that he died of strangulation and traumatic asphyxiation.

Carlson first called 911 to report that a man had been urinating near his house on Fourth Street, Snohomish County deputy prosecutor Cindy Larsen wrote in charging papers. About nine minutes later Carbajal called police, saying he wasn’t urinating. He was only walking through the alleyway.

A woman called 911 about 13 minutes later to report a fight outside her apartment on N. Olympic Avenue.

She told police that she saw two men, later identified as Carlson and his son Robert J. Carlson, 21, fighting Carbajal. All three men were throwing punches, she said.

The younger Carlson then drove off in his pickup truck. The fight continued between his father and Carbajal, the woman said.

Robert L. Carlson knocked Carbajal to the ground and sat on top of him, court paper said. The woman and her boyfriend both reported seeing the older Carlson choke Carbajal.

He yelled for help and the woman called 911. She said after she made the call, Carbajal didn’t move. Carlson got off the man and sat down on the curb.

She said she heard Carlson say, “I could kill you! I told you not to talk (expletive),” court papers said.

Robert L. Carlson spoke with detectives. He told them that he and Carbajal exchanged insults when he found him in his driveway. Later he saw his son being punched by Carbajal while the younger Carlson was sitting inside his pickup. He said he ran to his son’s aid and began fighting with Carbajal, Larsen wrote.

His son drove away and the fight continued. He told investigators Carbajal tapped his arm while he was being choked, indicating submission. He said he loosened his grip but continued to apply pressure, thinking that Carbajal was “playing possum,” court papers said.

Carlson told investigators he released his grip and got off of Carbajal when the man stopped moving. He said he checked for a pulse and he and his son discussed taking the Carbajal to the hospital, court papers said.

Police officers found father and son sitting on the curb, down the street from where Carbajal was discovered.

Robert L. Carlson told investigators he “took it too far,” and wanted to pay for his mistake.

Investigators were unable to get a statement from his son, who was too intoxicated, Larsen wrote.

Diana Hefley: 425-339-3463; hefley@heraldnet.com.