I have 2 daughters (8 and 4 years old) by the same man. We were never married, but I was the sole supporter of our family for 10 years in CA. He stayed home (against my wishes) to "care" for them... he did a fair to poor job. He is an alcoholic and drug addict, never seeking treatment, last DUI more than 7 years ago... Now he has run off to Mexico (7 weeks ago) with a teenager girl. We have had no contact with him. How do I file for full custody or child abandonment?

Hire an attorney or go to legal aid for your area and have them file for custody and child support.

This is NOT an issue of Child Abandonment There is a sticky note at the top of this forum that deals with that issue.

What is your ultimate purpose here. Since he has left, it would seem you have de facto full custody. So you need to define what it is you really want.