Take off her cape

You go over to the kneeling superheroine and take of her cape. It is only held in place by 2 clamps so it's easy to remove. You examine the fabric and find it to be nearly indestructible. You immediately have an idea.

You walk over to the mugger and the woman. First you remove the gun from his hands, unload the bullets and throw everything in a nearby trashcan. Then you remove his clothes, discarding these in the same place as the gun. You focus your attention on the woman. She's wearing a brightly coloured summer dress, brown boots and a red leather purse. You take the purse first and have a look through it, but can only find makeup, a phone and her wallet. You place the purse on the ground. You move her arms up over her head and remove her dress. To your surprise she's only wearing blue panties with the Wonder Woman logo on it. "Ironic," you say to yourself, kneel down and remove them too. You proceed to dump her dress in the same trashcan as before, but you keep the panties, thinking the will come in handy latter.

You move both of their bodies to a nearby streetlight and tie them to it using Supergirl's cape. You take a step back and admire your work.

You stopped a crime and also stripped a woman naked. That's a win-win. But wasn't there something you forgot.

You turn around and see Supergirl still in her landed pose.

"Oh, yeah! That will be fun."