Sam Lucas is a character from Ghost Whisperer.
Not much is known about Sam Lucas prior to his death, he had one sister named Jordan and two parents who were very controlling of Sam's life. He also had an ongoing off again on again relationship with a woman named Nicole. It is also known that Sam was an architect, but nothing else about his career or personal life.
Sam Lucas dies in a car crash and crosses over immediately, however Jim Clancy's ghost was at the crash site and looking for a body to step into in order to live again. When Jim enters Sam's body, he cannot remember Melinda or anything else about his previous life, not his parents or his sister, not even the woman he intended to marry. Eventually Sam starts to experience flashbacks, memories of Jim getting shot specifically. This memory was first triggered while he was at the hospital, seeing a patient with a shoulder wound made Sam's shoulder hurt as well and he remembered the night that Jim was shot.