Investigators say they do not know what led the suspect, Aaron Saucedo, 23, to launch his months-long shooting spree.
"This case plagued our community for more than a year and left behind a trail of victims that included mothers, sons, brothers, sisters and families still mourning the loss of their loved ones," police chief Jeri Williams told a news conference yesterday.
She said investigators worked round the clock to connect Saucedo, who was employed part-time as a bus driver, to the series of homicides.
Saucedo's first alleged attack was in August 2015, when he is accused of having shot dead a friend of his own mother.
He is later believed to have fired at random on complete strangers in the street, killing eight people. He is also suspected of firing into a house in a separate incident, an attack in which no injuries occurred.