Also, I'd be absolutely shocked if 'single party consent' applied to taking nude or sexual pictures of people.
It really boils down to usage. If he tried to use them for anything (i.e. blackmail), sell them, or distribute them then he would likely be in prison already. Based on the story they were entirely for personal use, which is again a gray area. For example if the footage is from security cameras in his house, he’s allowed to own that footage under single party consent. His home, his cameras, his consent. That doesn’t change unless a crime was committed in the film or the film itself was distributed in some fashion.
It really boils down to usage. If he tried to use them for anything (i.e. blackmail), sell them, or distribute them then he would likely be in prison already. Based on the story they were entirely for personal use, which is again a gray area. For example if the footage is from security cameras in his house, he’s allowed to own that footage under single party consent. His home, his cameras, his consent. That doesn’t change unless a crime was committed in the film or the film itself was distributed in some fashion.