It could be more detailed, but the headline is accurate, the DOJ jumped into the middle of this case when they didn’t have to (just like they did with the E. Jean Carol one until enough people called them on their shittiness to get them to reverse course) and now is volunteering to commit taxpayer dollars to pay any damages Trump could be found liable for as part of a broader effort to have this whole lawsuit because the DOJ really doesn’t like talking about police officers committing brutality after being ordered by their superiors to do so.

Justice Department attorneys said in a notice filed in federal court in Washington late Monday that Trump is entitled to U.S. government support in the civil case because the suit’s allegations stem from his work as president.

“On the basis of the information now available … I find that Donald J. Trump was acting within the scope of federal office or employment at the time of the incident out of which the plaintiffs’ claims arise,” wrote James Touhey Jr., the head of the Torts Branch in DOJ’s Civil Division.

Justice Department attorneys also filed a motion to dismiss the claims against Trump

Also,

I would think they should have stuck with suing The President rather than Trump even if that meant no financial reward.

I know they can and I’m pretty sure they are pursuing both forms of liability. Lawsuits usually involve plaintiffs making a bunch of different arguments with the expectation that one or more will get dismissed.