Assassination is one of Charles Bronson’s later films co-starring (you guessed it) real-life wife Jill Ireland.
Bronson is a secret service agent assigned to protect the First Lady of the United Stated (Ireland with a fairly wild afro going on). Her character doesn’t much like Bronson, or he her thinking he should have been given a much more important duty.
Someone then tries to kill the First Lady which sends everybody scuttling about and Bronson trying to track down the source of the assassination plot.
I think by about 1987 Charles Bronson’s career was starting to wane and this is not one of his best films, but however it is still very accessible if you are a big fan of his films as I am.