Is this traffic incident illegal?

The other day some jerk swerved in front of me and slammed on their brakes nearly causing me to run into them, Can I call the police and have them arrested?

You can call the police and file a report. If you have dashcam video that would make a citation more likely to happen. I don’t think I’ve ever heard of anyone being arrested for a traffic violation that didn’t involve death or injury… you know, unless you have evidence they were under the influence.

Again, sans contact, Police aren’t going to consider it a criminal activity in most cases. If you have all the documentation though, it might be worthwhile to report it just in case they caused an accident later in the day/drive. Though almost certainly more trouble than it’s worth for you.

You may have avoided insurance fraud there.

Yes, “brake checking” is illegal in almost all states. Whether the cops would do anything about it with our without evidence is another story.

This is true - and a good reason to report it if you have dashcam footage. Even if you only got the license plate it could be beneficial to report it to police.

You can call the police (non-emergency line, please). You cannot “have them arrested”.