I don't fit your demographic, however, my girlfriend at the time is central to the experience.

My GF in college was in an abusive relationship with a guy that was in prison when we met and started dating. When he got out he started stalking her and harassing her when I wasn't around. He would show up at her apartment and band on the door until a neighbor called the cops and then leave before they got there.

One after noon I caught him at her door and dropped a crippling beating on him. Three of the neighbors called 911 and one even gave my name. However, at the time of the call I was getting a speeding ticket six-blocks away. The officer had just called in my licence and registration when the call came over for an aggravated assault.

After getting my ticket, I hustled over to my GF's apartment. As I walked up to the lobby I saw a guy in a yellow shirt that looked very familiar. I remember thinking he looks like me. We looked at each and he walk around the corner and disappeared. I continued into the building and got arrested. The cop that wrote the ticket arrived as I was being handcuffed. He asked what I did and the sergeant told him I beat the guy in the stairwell. When he told them that he was writing me a ticket when the call came in, things got strange.

All the 911 calls said yellow shirt; I was in red. In one call you could hear the guy's get his legs broken; I was with the cop six-blocks away. My hands had no sign of punching anybody. Eventually, the sergeant reluctantly let me go. As asked them to come with me and tell the neighbors that I wasn't the guy. The talk with the neighbors went smoother than I thought it would. After the cops left, they told me that it must have been my doppelganger, and that he came and did what I could not do at the time. That was the first time I ever heard the term doppelganger.

I don't know if this matters, but if I had been five-minutes earlier, it would have been me working him up in the stairwell. So the doppelganger didn't do anything I wouldn't have done.