Brittany Hura, who was in a relationship with Cartwright for six years, made the alleged death threats in a video posted on her Facebook account on Sunday.
“You think I’m laughing because I’m mentally f***ed up?,” she asked in the video posted under the name Brinneyy Hura.
“I’m not mentally f***ed up I’m just laughing at you ... you’re going to be dead soon.
"In the grave ... six feet under ... you don’t even know what’s coming at you.
“Don’t worry about me I’ll be somewhere ... on CCTV.