Carlos Segovia died at 8 p.m. at California Hospital Medical Center, according to the Los Angeles County Medical Examiner-Coroner. Segovia had been hospitalized in grave condition since the weekend.
He was found at 11:35 p.m. Friday slumped over and unconscious in a Dodge Charger in the 2100 block of 31st Street, according to Capt. Peter Whittingham of the Los Angeles Police Department.
The Marine left the military base near San Diego on Friday. He had just visited his girlfriend that night and was preparing to drive to the home of Claudia Perez, a family friend, when he was struck by gunfire.
Perez said Segovia was like her child and he usually stayed at her home when he visited the area.
"He texted my son that he was bringing pizza home," she said. "He never made it."
Friends and family will hold a vigil for Segovia at 6:30 p.m. Tuesday at the site of the shooting, police said.
No suspect has been identified in the shooting. Police said Segovia has no connections to gangs or other activity that would seem to make him a likely target of gun violence.
Whittingham said the shooting is "absolutely a mystery."
"Like so many cases in South L.A., we have nothing to go on at this point," he said.
Segovia, who was born in El Salvador, came to the U.S. with his mother. Both are U.S. citizens, Perez said.
After graduating high school, Segovia joined the Marines about six months ago.
The U.S. Marine Corps identified him as Carlos Segovia Lopez, who held the rank as lance corporal. His current assignment was at the student reconnaissance training company. He earned the National Defense Service Medal and certificate of commendation.
A U.S. Marine spokesman said command has been focused on providing support to Segovia's family.
He was best known around his community for his volunteering and service work. Segovia led a youth group called Teen Project, which aimed to motivate high school students to finish school, and he worked at LA on Cloud 9, which provides services to homeless people and to animals, Perez said.
He once served as junior counselor for USC Troy Camp, a group that mentors children in South Los Angeles.
"We are heartbroken over this tragedy," LA on Cloud 9 said. "We were fortunate to witness Carlos become a fine young man who graduated from the Marine camp earlier this year and started his service with the US Marines."