Sam took Elizabeth in once her mother was killed and she was abandoned by her father. Sam became her adoptive father and cared for her, though she believes she cared for herself.
Sam was among the very few who knew that Raymond Reddington is not the real Raymond Reddington, but an imposter who took over his identity over 30 years ago.
Sam calls to tell Lizzie that he is having another test for the cancer. Lizzie tries to go, but gets caught up in work, so Tom goes to see Sam. Red goes to pay his respects, but smothers Sam to death when Sam tries to call Lizzie and tell her a secret about her biological father. Red later states that Sam was very sick and confused otherwise he would never have tried to tell her a secret that was too dangerous and that had not been his secret to share
Red tells Lizzie that the way Sam told the story was that one night an old friend turned up at his door scared who said he was leaving town and was in danger and that he needed somebody to care for a little girl (Lizzie). The girl's father had died that night in a fire and so Sam took her in and cared for her as his own and sheltered her from the truth about her biological father so that she would not be in great danger. Red tells her that taking Sam's life may have been the most difficult things he had ever done, but he did it to protect Elizabeth like Sam had done.
He appears in a flashback.
Sam's murder is shown in a flashback as one of the people murdered by the man known as Raymond Reddington to hide his secret.