COVINA, Calif. (KABC) -- A teenage girl was shot in the back of the head while walking with a group of friends in Covina Saturday night in what appears to be a random shooting.Authorities said the shooting was reported around 9:45 p.m. in the 4500 block of Heathdale Avenue near Cypress Street.The girl, who authorities believe is around 15 years old, was taken to a hospital. She is listed in grave condition and is not expected to survive.Authorities said the suspects were three men in a dark SUV.Investigators were looking into whether the shooting was gang related, but so far no evidence indicates that.The investigation is ongoing.