Cactus Island, A Stan Turner Mystery Vol 8

Stan is called out to Possum Kingdom Lake in central Texas where there's been a tragic Jeep accident. The teenage driver, Steven Caldwell, survives unscathed but his passenger dies. It appears to be just another tragic auto accident until the sheriff discovers Steven and the victim were in love with the same girl. When Steven is charged with murder, he insists the accident wasn't his fault. He claims he was distracted by an alien spacecraft flying overhead. At first Stan thinks his client's story is ridiculous, but as his investigation progresses he discovers his client may be telling the truth.