He was the last shooter with the cool spikey hair (probably a wig worn for the show) and was also shown standing by the bathrooms "watching them.."

I'll never forget that guy - I just thought of him as being badass even though I know he was protraying a killer. And nobody will ever convince me that in real life Berkowitz alone killed all of those girls and Moskowitz.

I don't know who played that guy but he was wearing a wig. the real shooter wore a wig also (it's mentioned on UM and in Maury Terry's book "The Ultimate Evil"