Hello bmd, big hugs to you. I've met many people over the years who take drugs (often friends of friends etc). Simple advice: Don't trust heroin, crack or meth. They turn good people into liars and thieves (in my experience, 100% of the time). Sometimes people get clean and can become wonderful people again, but it takes a long time.
If I recommended this person to you as a blind date, with the information you included in your post, would you accept?