Bishop73

Answer: There are 30 years separating Frank and John, but it seems that the timelines are parallel and unfolding at the same time. Example: if something happens on October 10th 1969 at noon for Frank, any repercussions from that will unfold for John at October 10th 1999 at noon. We see evidence of this when Frank burns the desk, when he survives the fire, when he shoots Jack's hand off, etc. After Frank survives the fire, he comes home and has a conversation with John. After they talk, John calls his mother (Julia) and gets her answering machine. Then, keeping in mind this is happening in a parallel sense, young Julia in 1969 saves the life of her killer, setting in motion a new future in which she is killed. It is then when a sleeping John in 1999 starts getting memories of his mother's funeral. So, when he called and got her machine earlier, she had not yet saved her killer's life in her timeline. After she does save his life, John wakes up and tries to call her, but gets the deli instead.

jshy7979

Answer: John calls his mom, which goes to voicemail, before he uses the ham radio where he ends up talking to his dad. At that point, the timeline hadn't changed, his mom was still alive and his dad still died when he was a kid. The timeline changes (along with getting new memories) after his dad decided to listen to John's advice and make different choices.

Bishop73

Answer: Florence Nightingale is considered the founder of modern nursing and nurses are often called "nightingales." It has nothing to do with Jack's mother telling on him or "singing like a bird." Whether or not Jack killed his mother is left ambiguous, but it does seem like that's what they are suggesting. In the film we are told Mary Finelli was his first victim. However, they seem to imply that Jack's mother's killing was not associated with the "Nightingale Murders." Had the police connected her murder to the "Nightingale Murders", it night had led them to Jack. So Jack changed his M.O. after killing his mom, which I take as targeting younger nurses. In the film, Jack's dad tells John that Jack got caught up in the Knapp Commission, which was an investigation into police corruption. Jack went to prison, which is why he stopped killing. In the film, it's suggested that perhaps the killer (before they knew it was Jack) was taken off the streets (i.e. sent to prison for a crime not related to the killings) and smartened up once he got out of prison. There's no suggestion that age or lack of testosterone is what stopped Jack from killing after getting out of prison. Of course, it's also possible he did kill again, but due to the gap in killings, those murders aren't related to the "Nightingale Murders." But all that is speculation since they don't really reveal any of that information and it's not central to the plot.

Bishop73

Answer: I can answer part of your question. Most serial killers are under the age of 50. Testosterone levels drop after that age, and it is thought that this may reduce a psychopath's urge to kill. The nightingale reference may be the same as the slang term, "to sing like a bird," which means someone gives up information easily. Jack's mother may have provided info about her son, either knowingly or unknowingly.

raywest ★

Answer: Or maybe Jack's mother abused him as a child, and that's why he hated her and killed her, and then became a psycho serial killer. He continued to kill other nurses because his mother was a nurse.