On Sunday, a right-wing militia member helped federal officers chase, pin down, and handcuff a protester who tried to enter the pro-Trump rally at Terry Schrunk Plaza. The feds are now investigating.

"The incident involving the private citizen is under review with the US Attorney's Office," DHS spokesperson Lucy Martinez tells the Mercury.

The man—working security for the rally—is seen on multiple videos assisting DHS police officers from the Federal Protective Service arrest the guy. At one point, he unfurls a zip-tie handcuff from the federal agent's belt before handing it to the agent, who then puts them on the wrists of the guy who's pinned down.

It was captured on video by a blogger (the main action starts at 1:17 or so)

It was also captured by Oregonian reporter Jim Ryan.

And it was photographed by OPB's Bryan Vance.

I forgot I caught this image of an oathkeeper (serving as private security for the pro-Trump crowd yesterday) help… https://t.co/f1jAgk1GNx pic.twitter.com/2RRC4xz7Iy
— Bryan M. Vance (@BryanMVance) June 5, 2017

The man appears to be a member a right-wing militia group. The group has run security at previous pro-Trump rallies in the area. Terry Schrunk Plaza is federal property and the pro-Trump rally had a permit from the federal government to be there.

Here's what the DHS's Martinez tells the Mercury about the arrest:

The Federal Protective Officers were in the process of removing an unauthorized protestor from the demonstration. FPS officers were operating within the scope of their authority to ensure the safety of all persons and support the peaceful expression of their 1st Amendment rights.

The incident involving the private citizen is under review with the US Attorney’s Office.

Though the Portland Police Bureau (PPB) had nothing to do with this specific arrest, we asked PPB spokesman Pete Simpson if they have a policy on this sort of thing:

I’m aware of the image/video and it is FPS/DHS. My understanding is that event organizers were asked to make clear that nobody should interfere with or get involved in arrests. Not sure what the scenario is on this arrest so you’d have to check with FPS. There’s not really a PPB policy about this kind of thing but as a practice, we’d prefer not to have private citizen involvement in an arrest but there have been times where private security (think bar bouncers, loss prevention, etc) have jumped in to assist an officer struggling with a suspect.

We'll update this post when more information comes in.