Driving home saw a chick getting thrown to the ground by a guy. I intervened. What now?

So I'm driving home from a party and saw a SUV half in the road, lights off, all four doors open. Then I see a chick and a guy on top of her getting thrown to the ground. I didn't even think, I slammed on my brakes, threw it into reverse, and ran over. When I got there, the chick and the guy were against the car, she's pushing at him, he's pushing back, and I hear babies crying.
I ask if everything's ok, the woman's hysterical, the man's obviously pissed, and I step in between them and push them apart. I order the man to step away from the vehicle, tell the woman to do the same, and she's screaming that he's trying to take her babies. At this point, I push the man away from the vehicle firmly, and guide him to the curb. He's bleeding, multiple lacerations to the chin, forearms, and shins. He claims she pushed him out of the vehicle while it was moving, and she's on the phone with the cops.
Once I confirmed that the cops were on their way, I strenly told the guy to stay put and sit on the curb. He appears to be compliant, and the woman runs out INTO TRAFFIC screaming and wailing. Traffic stops, and I grab her by the shoulders and guide her back out of the road. At this point, the kids are crying, the man's trying to comfort them and I try to figure out if either of them has keys to the vehicle. They both keep trying to tell me their side of the story - I don't care, the car's dark and half in 60 mph traffic - we need to move it out of the lane.
The woman wanders into traffic again, and I try asking her where the keys are, as she says the guy doesn't have them. The man takes the opportunity of traffic being stopped to get into the drivers seat. He starts pulling it towards the curb, then floors it and takes off.
I dragged the woman into my car, she gets on the phone and I tell her to tell them to issue an Amber Alert and give a description of the vehicle. I floor it and try to chase him, but lost him at a round a bout. No clue where he is, I slow down to a reasonable speed, and we spot a cop with lights on. I honk and flag them down, we tell them what happened (the woman still hysterical) and she gets a call from the man.
At that point, the cops had the situation - I gave them my number, the woman gave me a hug, crying and saying thank you, then they took off.
I'm still shaking, two hours later. What. The. Fuck. So what should I expect now? I didn't have to get physical with either of them beyond taking them by the shoulders firmly. The guy took advantage of me calming the woman down to carjack her. I feel horrible that it happened, when I'm trying to help, but at the same time the cops apparently caught him pretty fast.
I'm going to bed. Just needed to write everything down while it was clear in my mind.