A 60-year-old man who was stabbed last weekend in San Marcos has died of his injuries, authorities reported Friday.
Deputies responding to a report of an assault about 6 p.m. Saturday found Martin Mendoza of San Marcos gravely wounded in a parking lot in the 200 block of West San Marcos Boulevard, according to the San Diego County Sheriff's Department.
Paramedics took Mendoza to a hospital, where he succumbed to his injuries two days later, Lt. Chris Steffen said.
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Based on witness statements, deputies arrested the suspected assailant, 23-year-old Dahlia Silvia Perez, near the scene of the stabbing. She was booked into Las Colinas women's jail in Santee late Saturday evening on suspicion of attempted murder.
Following Mendoza's death, that charged was upgraded to a count of first-degree murder.
The reason for deadly assault remains unclear.
"The relationship between Mendoza and Perez is still unknown," Steffen said Friday. "The motivation and circumstances are under investigation."
Anyone with information on the incident has been asked to call the Homicide Unit at (858) 285-6330 or after hours at (858) 565-5200. You can remain anonymous by calling Crime Stoppers at (888) 580-8477.