word choice - "Is" vs. "was" for occupations that are indefinitely paused?

I've been binging Criminal Minds on Netflix recently. The season six character Ashley Seaver is the daughter of a serial killer. He's in jail in North Dakota, which doesn't have the death penalty. He stopped killing when he was arrested, but since he's still alive, he could kill again. Which sentence is correct:

1. Her father is a serial killer.




2. Her father was a serial killer.

Also, would that same construction fit occupations/callings/professions? Say, a retired doctor? Perhaps a soldier who's been discharged but can still be called to active duty? A biker who doesn't currently own a motorcycle?