Hi Dodge, you are indeed stuck between a rock an a hard place. At least, you have doubts abd are aware of his friends "situation". You can now keep an eye open. As he doesn't have custody of your child, you can feel "safe" in that respect. If he ever wants custody ir access, you can see then what can be done to prevent that.
Until then, I would make sure there is now way he can have access or contact with your child. Make sure he can't go to the school, that no family member will ever let him within 10 feet of your child, etc.