Can my sons grandmother be granted sole custody of my child?

Q: Back in 2007 my children were removed by acs because my son walked out of the apartment for the second time around when he first walked out of the apartment it was while he was under my daughters father supervision and acs asked for proof of my reason to why I left my daughters father in care of my son then 3 months later he walked out of the apartment while he was under my supervision. On 2010 my sons father was awarded custody of my child and dissapeared with him on January and July of 2012 he allowed me to see my son after many attempts of me trying to get a hold of him in order for me to visit with my child I also petition twice once for visitation rights and then for custody but, I then find out on Nov 19th that my sons father passed away and the family won't return him back to me. 

A: David’s answer: You have a right to file for custody, however ACS also has a right to be heard on that application if there was a prior finding of neglect. Thus, you should be prepared to demonstrate what efforts you have made to rehabilitate yourself from the time when the original neglect case occurred.  -- David Bliven