In S1E15, Christopher announces to Lorelai, after a disastrous night at her parents’, that he wants to marry her. She freaks out, at one point yelling, “Charlie Manson is freaked out by you right now!”
Charles Manson led a cult-like group of followers to commit 9 murders in California in 1969. He thought he could start an apocalyptic war with the murders, supposedly. As of 2016, he is still alive in prison, serving multiple life sentences.