No. 1. Up your management. Expect that the next time he gets out of your house, he will bite someone, the police and animal control will be called, and your dog will be ordered to be euthanized, and you will then be sued.
No. 2. Find the money and take your dog to a trainer. You need to train him and bond with him and get him under voice control. The more you work with him, teaching him praising him for doing the right thing, and letting him know it if it wasn't quite right, and being consistent in your body language, voice praise or correction, your dog will gain more and more confidence in you. When that happens, he will become less of a danger to others.
Keep him safe. If you choose to begin to socialize him at this point, go slow, and start with people or things you believe he will succeed with.
Clickers snickers! load your praise with treats, and then start phasing out the treats. Praise is free, you never run out, and you can't lose it before your walk.
Work with a good trainer who can explain what body language you are conveying to your dog, and work consciously on being consistent.
Jenna, RN CGC & Babs, CD RA CGC HIC
Heidi, RA CGC
SG3 Odessa, SchH1, Kkl1, AD
Ninja, RN CGC & Milla, RN CGC
Joy, Star Puppy, RN CGC
Dolly CGC & Bear CGC