gerald cowan was later convicted of manslaughter for killing his father-in-law. he served only two years in prison for that crime before he was released on parole. prosecutors believe robert cowan was one of the men sear the mercks' home by the neighbor. based on forensic evidence, prosecutors say robert cowan and an accomplice broke in to the mercks' home through a back door. cliff merck probably went for his gun to defend himself, and robert cowan grabbed the pistol and turned it on cliff. [ gunshots ] >> the men bound his wife alma, locked her in the closet, and left her to die. robert cowan left his fingerprints on a tray found in the living room. and by the back door as he left. the cowans pawned some of alma