An Upper Gwynedd veterinarian accused of shooting and killing his pregnant mistress has had a court appearance delayed. 30-year-old David Rapoport was set to have a preliminary hearing next week, but now it has been moved to May. He has hired new lawyers to defend him against criminal homicide charges in the deaths last month of 27-year-old veterinary technician Jennifer Snyder and her unborn child. She and Rapoport worked together at one time at a veterinary practice in Lower Macungie, in Lehigh County. Court documents say the two had an affair for three of the six years he was married to his wife, Elizabeth.