The meaning and relevance of this movie's Murphy's Law (1986) title is that it is a play on words of the central character's name Jack Murphy (Charles Bronson) with the popular expression of the same name that in simple terms states anything that will go wrong, will go wrong, a maxim that can be considered to apply to the Jack Murphy character in this movie. The character even has a variation of Murphy's Law in the movie and that's Jack Murphy's Law which his character says is: "Don't f*** with Jack Murphy!".
This movie teams a cop Jack Murphy (Charles Bronson with a thief Arabella McGee (Kathleen Wilhoite). This storyline of pairing a cop with a convict was popular in Hollywood during the 1980s after the success of 48 Hrs. (1982). This high-concept was encapsulated in one of this film's movie poster tag-lines reading: "He's a cop, She's a thief, together they're running for their lives". During the 1980s, Midnight Run (1988) also utilized this high-concept but replaced the cop with a bounty hunter. The convict-cop pairing was also earlier made famous in The Defiant Ones (1958).
This movie was one of two films that starred Charles Bronson and released during 1986. Act of Vengeance (1986) was the other movie (made for television) and interestingly, both were first released in the USA during April of that year.
Carrie Snodgress, Academy Award Best Actress Oscar nominee for Diary of a Mad Housewife (1970), creates a variation of her famous "Mad Housewife" screen persona in this movie by playing a "Mad Villain" who is a psycho killer who actually frames Jack Murphy (Charles Bronson) by murdering his ex-housewife!
Rock singer Joan Jett auditioned several times for the Kathleen Wilhoite role. Jett nearly got the part but was edged out due to her lack of acting experience. However, a friendship between Jett and Charles Bronson (and Bronson's wife, Jill Ireland) lasted until his death.
This movie was made and released about two years before "Murphy's Law" (1988), a tv series that shared the same name. It was also made and released about two years before the similarly titled Murphy Brown (1988).