Okay, in that case he has no way to offer to help with the wounded.

Apparently not. They're in a hurry to back off somewhere else, apparently. Maybe worried about reinforcements.

Anyone left to stabilize? Anything still on fire?

Red Cape is still alive. A trash pile is on fire.

...A convoy of black trucks rounds the corner three blocks away, gunning for this spot!

He stabilizes Red Cape. He puts water on the trash pile. ...he casts Comprehend Languages in case he's about to need to put his hands up again.

Yeah, more troopers pour out of the trucks and spread out to secure the whole area. They chatter orders in a dense artificial language that has two syllable words for concepts like 'set up a cordon'. 

Four go straight for him. "On the ground! Hands behind your back! ON THE GROUND NOW!" And they're not waiting for him to reply, they're rushing right for him and are going to try to cuff his arms and legs.

Well, he's going to do his best to cooperate with that, okay.

He is manhandled into a truck - surprisingly gently, all things considered - and relieved of the mace but not the holy symbol. The mace goes into a hard case.

A different Red Cape- His jaw structure and skin tone is a bit different, but the armor is near identical (sans bullet damage)- Comes over after a couple minutes.

"You are under arrest on suspicion of terrorist activity. We don't have records of you in our systems and you were found in the aftermath of an attack."

"Systems?"

"Our face recognition ID system has no record of you. You have never registered as a resident of any ADVENT sector or been entered into it for any other reason. This in itself is not illegal. You are not required to register to live in a border sector. We know that there are many people still living outside the sectors while we work to expand what ADVENT can offer. However, it is an exacerbating factor given the dangerous dissident activity that continues to this day. Can you explain how you came to be at the site of a violent incident?"

Literally speaking, no, he can't, not with his hands cuffed. He shakes his head.

"Why not?"

"Because I don't speak your language and am only understanding you with Comprehend Languages," he replies in Chelish.

"Are you capable of understanding but not speaking English?"

Oh, he's quick on the uptake, convenient. Nod nod.

"I'm not trained for this kind of interrogation. Is there a way, accessible quickly, and reasonable, to allow you to communicate effectively? Such as writing materials or a translator to another major language?"

"Mm -" He rattles his handcuffs.

"Uncuff his arms, then return to guard position." He barks out in that other language, to the black-armored trooper lurking ominously behind him. 'Return to guard position' is one syllable.

Black trooper does so, silently.

Will Red Cape take his hand?

This is far outside of normal operational parameters. He has only guesses. And guesses do not make good policy decisions.

After a few long moments of consideration, a few facts reign supreme. One. He is but one unit of many. Far less replaceable than the troopers, but still not unique. Two. Information on the dissidents, their capabilities, their activities, their motivations, is very valuable to ADVENT. Three. Training emphasizes gestures of confidence, cooperation, concession, and sympathy when interacting with the public in order to reduce willingness to rebel against ADVENT.

He will grasp the offered hand.

"Share Language."

"Unexpected."

"I apologize, I couldn't think of a way to explain in advance. That will last twenty-four hours. I have another one if there is someone else I should preferentially speak to, and several of the one that only lets me understand, which lasts almost an hour each time."

"I am capable of and willing to communicate on behalf of the ADVENT* organization. While my superiors confer, my original question: Why were you present at the site of a violent incident?"

*Spoken phonetically as 'advent', not translated.

(And the officer's mental implant tells him: Delay. Psionic unit has been dispatched to evaluate the person of interest.)

"To see if I could help. I didn't find the situation clearly legible so I didn't intervene in the fight, I just stabilized downed combatants and put some water on the fire."