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A 56-year-old man has died after he allegedly tried to carjack a tree-trimming truck while it was moving and the driver successfully fought him off in San Marcos on Saturday, sheriff’s officials said.
The incident occurred when the man — allegedly armed with a knife — jumped onto the running board of a Freightliner tree‑trimming truck in an attempt to forcibly take the vehicle on Pacific Street near Grand Avenue around 5:40 a.m., said sheriff’s Lt. Juan Marquez.
Due to either the window or door being open, the driver of the truck then got into a fight with the carjacker, Marquez said. At some point, the man fell off the side of the truck and into the roadway.
The driver immediately called 911, and paramedics arrived, according to Marquez. They found the suspect lying in the street with a serious head injury.
He was taken to a hospital, where he died Monday. He was identified as Mark Douglas Heninger, a San Diego County resident, Marquez said.
The driver stayed at the scene and spoke with investigators. He suffered minor injuries but declined medical attention.
Marquez said it appears Heninger was not run over or struck by the truck, but investigators are waiting on the county Medical Examiner’s Office to determine the cause and manner of death.
“The circumstances and motive surrounding the incident remain under investigation,” Marquez said in the release.
Homicide detectives are continuing to gather video surveillance and review footage they have already received, Marquez said.
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