Francisco Hernandez, 19,suspected gang member has been arrested and charged in a shooting

Francisco Hernandez, 19, was charged with murder and attempted murder in the Sept. 19 shooting that killed Marco Casillas, 19, and wounded his 19-year-old girlfriend.suspected gang member has been arrested and charged in a shooting that killed a man and injured his girlfriend as the couple walked their dog in Oakland, authorities said today.The two were walking a dog on the 4000 block of Santa Rita Street when someone opened fire on them at about 10:45 p.m.The woman's mother realized that something was wrong when the dog came back to the house alone with blood on its fur, according to Casillas' family.Casillas and his girlfriend were found lying on the sidewalk. Casillas was pronounced dead at Highland Hospital in Oakland.Casillas had hoped to be a dental assistant and was working at an Alameda pizzeria, relatives said.A motive for the shooting was not known. Authorities said Hernandez is a gang member but that the victims were not.Hernandez was arrested Dec. 29 at an Oakland home and is scheduled to appear in Alameda County Superior Court on Feb. 2. He is being held without bail at Santa Rita Jail in Dublin.