Three of the suspects -- Martin Melendrez, 19, and Michael Zarita, 19, both of Vista, and Santo Diaz, 18, of Oceanside -- were being held in the county jail in Vista. The fourth, a minor whose name wasn't released, was taken to a juvenile facility, the Los Angeles Times reported.
They are charged with two counts of murder, two of attempted murder and two counts of participating in a criminal street gang for the March 13 shooting deaths of Melanie Virgen, 13, and Edgar Sanchez, 15, and the wounding of two other teens in Libby Lake Park.
Investigators had yet to provide a motive for the shootings in the park where two other teens were gunned down in May 2011. Three suspects await trial in that case, the Times said.