Updated

Police have arrested a 17-year-old suspected of being one of two gunmen who opened fired on a car in the San Francisco Bay area, killing a 3-month-old boy in an attack authorities said Monday was prompted by a case of mistaken identity.

The incident early Sunday was an apparent retaliation for a beating the teen received last week in a gang fight, East Palo Alto acting police Capt. Jeff Liu said.

Police say the teen and another gunman shot up the vehicle — killing 3-month-old Izak Jesus Garcia-Lopez — after mistakenly thinking two people inside had been involved in the fight.

"But they were not," Liu said at a news conference to announce the arrest.

Izak's parents were wounded in the shooting. His 4-year-old brother, Isaiah, who also was in the car wasn't hit. The family was headed home at about 1 a.m. Sunday after attending a baby shower, police said.

Ivonne Garcia Lopez said tearfully that she was trying to protect her children during the shooting. She said she later noticed Izak was bleeding and had "a hole in his head."

"He was such a precious thing," she said Monday at the news conference. "He was my everything. I was really happy to have him in my life. We were happy and then this person came into our lives to destroy — they destroyed my family. They killed my baby. They killed a part of my soul."

She and her husband, Oscar Jimenez, are expected to recover.

The teenage suspect and a 16-year-old boy were arrested Sunday in East Palo Alto on weapons charges after police searches found three handguns — including the weapon believed to have been used in the shooting, Chief Ron Davis said.

Both teens were interviewed and the 17-year-old, who strongly resembled a composite sketch of one of two suspects police were seeking, "implicated himself" in the homicide, Liu said.

Both are being held in juvenile hall as while the 17-year-old faces possible murder charges, the 16-year-old remains a strong person of interest in the incident, police said.

Their names have not been released.

Authorities have not determined whether the teens would be tried as adults.

"We're going to seek the most appropriate punishment available," Liu said.

The shooting remains under investigation.

East Palo Alto Mayor Carlos Romero on Monday thanked the community for helping authorities.

"When I visited the mother in the hospital I promised her we would spare no resources to bring to justice those perpetrators," Romero said. "Today, I can say we met that promise."