A 56-year-old man died from head trauma after attempting to hijack a moving tree-trimming truck in San Diego County, California, with authorities confirming the driver fought back in self-defense and will face no charges in the incident.

Fatal Carjacking Attempt Unfolds on California Street

Mark Douglas Heninger jumped into a Blue Wave Tree Care truck while brandishing a knife early Saturday morning on South Pacific Street in San Marcos, according to the San Diego County Sheriff’s Office. The attack occurred in the 200 block as the vehicle was actively moving through the area. The driver immediately defended himself against the armed assailant, leading to a physical confrontation inside the moving truck. During the struggle, Heninger fell from the vehicle onto the roadway below, sustaining severe head injuries in the fall.

The truck driver called 911 immediately after the incident and remained at the scene to cooperate with authorities. Paramedics arrived and transported Heninger to a local hospital, where he later succumbed to his injuries. The driver suffered minor injuries during the altercation but declined medical treatment at the scene. Investigators determined that neither alcohol nor drugs appeared to be factors in the attempted carjacking, though the medical examiner’s office continues working to confirm Heninger’s official cause of death.

Criminal History Emerges as Investigation Continues

Court records reveal a man matching Heninger’s name and age maintained a lengthy criminal history stretching back to 1996, spanning three decades of documented offenses. Homicide detectives continue investigating the incident, though the suspect’s motive remains unclear. The sheriff’s office has not released additional details about what may have prompted Heninger to target the tree-trimming truck specifically or why he chose to attack a moving vehicle. Authorities have asked anyone with information about the incident to contact the San Diego County Sheriff’s Office directly.

Self-Defense Rights Under California Law

California law permits individuals to use reasonable force to defend themselves against imminent threats, including during attempted carjackings or armed robberies. The driver’s immediate response to an armed attacker entering his moving vehicle falls within legal protections for self-defense actions. Prosecutors typically evaluate whether the force used was proportional to the threat faced, considering factors like the presence of weapons and whether the victim could safely retreat. In this case, authorities have indicated no charges are expected against the driver, who acted to protect himself from a knife-wielding assailant who entered his vehicle without permission.