Joe Darley is younger brother of Billy in 2007 film Death Sentence.
He was portrayed by Matt O'Leary. Joe killed Brendan Hume by slicing his throat during a robbery by his brother's gang, and was arrested by the police. He was later the charges were dismissed by the court and he was released as his brother and his gang welcome him. Brenden's father Nick tracked down and comforted Joe for his son's death. When Joe taunted him when he cut his hand, Nick kills him by accident which left Billy's motive for revenge against The Humes.