Do i trust my kids father?

Hi IM's!
Im a single mum to 3 beautiful children and i guess what im trying to figure out is do i give their father a chance to be in their life. Now before anyone jumps down my throat of 'they deserve both parents' Hear my story first please.
Me and my ex started dating about 6 years ago. I pretty much fell pregnant with my first child straight away unplanned so was a bit of a shock, he wanted me to terminate the pregnancy i refused, he stuck by us. We had argument after argument and he always used the baby and pregnancy in a horrible way. So fast forward baby number 2 same thing ( yes i was on birth control and yes we took other precautions) but again he acted the same, i thought it was weird for him to do as he was madly in love with our first son. My daughter was born and everything went a little bumpy. He was never home, he didnt want us anymore, he 'hated' the kids, he would snap at everything our son or myself did wether right or wrong, he never wanted to hold the baby. We went through counciling and he 'decided' to love us all again?? Anyway me being stupid and wanting mu kids raised in a family i stayed with him and yes i fell pregnant yet again and this is where it just went too far. I told him i was pregnant, as my daughter was only over 1 i was worried it was too close but went through with it anyway! He told me he wanted the baby and he seemed extremly happy even went and brought a first outfit for it. But then at about 4 months pregnant, he snapped. He went overboard, he threw all my belongings outside and kicked me out for the night but wouldnt let me near my kids. I ended up calling the police and they removed me and the children and gave us a 24 hour restraining order to cool down on both ends. I contacted him before going home to ask if he would like to chat, he agreed. We went to a public place so i felt safer and he told me how sorry he was etc. i told him i wanted to stay at my mums house for a few more days just to make sure he was really calmed down etc.I went home to get a couple more things and i didnt think he would be home but he was, (this was after the restranining order was over) I grabbed mine and my kids stuff but he grabbed it off me and ended up pushing me over! I got up as fast but safely as i could and just ran out the door. When i got to the car he jumped on the bonnet and started saying he will kill me and the kids and shouting all sorts of horrible things. So i left him ompletely with the help of police. We went to court about custody of the kids and they granted me full custody as he was unfit to parent but he could have supervised visits with his parents and the kids grandparents. But he told me he wanted nothing to do with the mistakes he made over 6 years. It broke my heart to hear but what could i do. Me and the kids have been without him for over a year now, he hasnt seen or heard of them. I gave him opportunity after court but gave up. Recently, he contacted me asking to see the kids. He claimed that he was sorry and he didnt mean to hurt anyone and he would never hurt the kids etc.
so i guess what im saying is do i think about giving him a second chance or do i leave him out completely now? I dont know wether i trust him unsupervised but should i be giving him supervised?? please help im lost!
Sorry about the long post, thankyou!!