The story opens in 1974 but the song playing in the background on the record player is "New York Groove" from Ace Frehley's 1978 solo release and even the original by the band Hello was not released until 1975.
Leon: [to his son, Frank]
Listen, your mother... your mother was a bitch. She was a real bitch. She beat the shit out of your brother and sister on a daily basis with whatever she had in her hand. She was a violent drunk, she was a twisted fucking slut.