State police arrested three suspects Thursday night and early Friday in the sniper slaying of a 14-year-old girl who was killed riding to a high school basketball game on Cape Cod last weekend.

State police said William Ferreira, 42, of Wareham was arrested at the state police barracks in Bourne where he was being questioned in the death Saturday morning of Robyn Dabrowski of New Bedford.Caren Stenroos, 32, also of Wareham, was arrested at her home and charged with being an accessory after the fact of murder in the shooting, which occurred on Route 25 in Bourne, state police Lt. Lee Garrison said.

The third suspect, Scott Chipman, 24, was arrested just after midnight at his Dennis home, state police said.