If my friend reported their car stolen after I crashed it, what legal actions can they take against me?

Question Details: This summer I had a car accident in my friend's car that I only use to do him favors; the car was totaled. After that I paid the deductible and whatever payments where left on the car. He's now contacting me saying that if I don't give him $1,300, then he will report the car as stolen and I could face legal problems. I asked him to send me all the information regarding the car payments and the debt but he refuses to send me all the information. And he's been constantly threatening me the past 3 months even after sending him over 1k.
