I would only list related work experience, althought if he has none (or one position) that will make for a thin resume.
I'd only list certifications that are significant. Example: list the state certification as a police officer. i would not list stuff like OC spray, baton, firearms qual, etc.; though again that makes for a thin resume. I would not include copies.
Martial arts experience, if properly worded and inserted in the correct area, could be beneficial.
He understands very few places will accept only a resume, right? In LE, it is basically an addendum to the application.
"A man turns his back on the comforts of home, and when the dust all settles and the story is told, history is made by the side of the road..." - DBT