Can his rights be provoked if he tries to take me to court to determine paternity of my son and it comes back he's the father?

My ex has been absent from my son’s life for the past 9 plus months. When my son was born, I allowed him a few visits because I was trying to determine the situation and who the father was. He came a few times and then lost interest and left town. Nothing was through court. My son is 11 months old now. My husband is a potential father as well, but has been around since my son was born, and before. After we got married, he was put on the birth certificate and has been supporting us and been around ever since. My ex has never had any interest and has many issues: mental issues, depression, drug use, suicidal, and has harmed animals, and mentally and verbally abusive. He also has threatened me physically in the past. He has never come around or had interest until he found out I was married, then showed up in my town and supposedly has papers for me, but still hasn't contacted me, and it's been 3 plus weeks. I fear for the safety of myself and my child around this person. Please help.