16-year-old Livermore resident, in connection with last weeks downtown stabbing that left nearby Amador Valley High School on lockdown.
The victim may have been stabbed because assailants mistook him for a member of a rival gang, police said.
The suspect, whose name is not being released because of his age, was arrested on suspicion of assault with a deadly weapon. Witnesses helped police identify the teenager over the weekend, and he was arrested at his Livermore home.
A third youth who was spotted fleeing on foot with the 16-year-old still has not been located.
Police made their first arrest Friday, booking Jose Perez, 20, of Livermore on suspicion of assault with a deadly weapon after a 26-year-old Hayward man was stabbed on Main Street just south of Amador High.
Officials secured students and staff members at the high school until police secured the scene. No Amador students were involved in the incident.
Perez, who allegedly fled the scene in a white Ford Mustang, was taken into custody after police stopped his vehicle nearby.
According to police, the stabbing victim said he and a friend were driving through Pleasanton on their way to Amador Valley High School, where they planned to pick up the friends brother from school.
The passengers in the Mustang, one of whom was wearing a blue bandana, began shouting gang epitaphs and flashing hand signs.
It is believed this fight was the result of passengers in the white Ford Mustang believing (the victim) and his friends were affiliated with Norteno street gang, Pleasanton Det. Daly Harnish said.
No gang affiliation
One of the passengers in the victims car was wearing a red shirt his work shirt from a Pleasanton tire store. Investigation showed that occupants in the victims vehicle had no gang affiliation, Harnish said.
There was some assistance from the Livermore Police as far as their affiliation. They are familiar with the gang and have had contact with them before, Pleasanton Det. Daly Harnish said.
When the vehicles arrived at the intersection of Main Street and Del Valle Parkway, the occupants of both got out and began fighting.
The stabbing victim was transported to an area hospital and underwent extensive sur-