By Richard Winton and Lila Seidman From Los Angeles Times LOS ANGELES—The lives of a young model and an architect in Los Angeles were cut short when they were allegedly given an overdose of drugs and left for dead at nearby hospitals, officials said this week. Christy Giles, 24, and Hilda Marcela Cabrales Arzola, 26, both died under suspicious circumstances in November, prompting an investigation. The Los Angeles Police Department on Thursday announced that three men have been arrested in connection with their deaths. David Pearce, 37, was arrested on suspicion of manslaughter. Brandt Osborn, 42, and Mike Ansbach, 47, were arrested on suspicion of accessory to manslaughter. All three were arrested by the LAPD-FBI Fugitive Task Force and Metropolitan Division on Wednesday. According to police reports, homicide detectives began investigating after masked men dropped Giles off at a hospital in Culver City on Nov. 13 and sped away in …