Do I have the right to restrict visitation if I feel my child is in danger with my ex?

The law says that you can withhold visitation if the situation rises to the level of "serious endangerment." I have had plenty of judges tell me that it's called "serious" endangerment for a reason. Violence like you're describing is a close call for some judges. If it happens frequently, start calling the cops when you go to pick up your child. And, let the police talk to the child about he witnessed.

You need to get some kind of evidence to support your refusal to allow him visitation. You can do it without evidence, but if he goes to court filing a petition for visitation abuse, or for a rule to show cause heairing, you're going to have to prove to the court WHY you withheld visitation. And the judge won't support your position if you do it just on a hunch. A police officer testifying on your behalf that he made a report of violence, and your child was scared by it goes a long way in a court proceeding.

Is your son telling you that he's scared to stay there? does he tell you about their fights and his dad throwing things? If yes, take him to the school, and let him tell the principal, and his teacher about it. If he's six, he should be in school, unless you left something about this out of your question. Again, someone else to testify about what the child said is very powerful because they are uninterested parties, not a mom who might be biased about dad and his new girlfriend.

Or maybe you'll get lucky and can find dad's old girlfriend who has been the subject of his violence and is willing to testify because she really thought your son was adorable. Hey, stranger things have happened. Or maybe dad's new girlfriend will get fed up, and be willing to testify for you. Always be nice to the people who are involved with your children. remember, they are there to protect your children if and when necessary. The fact that she called you to tell you to come get your son is HUGE in my book. Keep her on your side.

Good luck