Wow, is this not a post I anticipated writing today. I was just out at lunch with, among other people, an off-duty DC police officer. As we were getting out of the Metro station in Foggy Bottom, someone shouted "stop him!" and a young man came racing down the escalator, tripped, got up, and took off again: my friend took after him, and I followed him back downstairs to make sure no matter what happened, he would be all right. An on-duty officer and a Metro security officer joined my friend in talking to the victim to get a description of the man who, as it turned out, had grabbed his phone from him, pushed him down, and taken off. My friend and the victim managed to come up with young, African-American, black jacket, dreadlocks. And the only thing I could add was that I'd noticed, even in that confused and very quick moment, that his dreads were thin, and somewhat messy.
They caught the guy, and it turns out I was right, my memory hadn't failed me, my brain hadn't compensated for my nervousness by inserting images that weren't actually there. I'm really astonishingly lucky: I've never been a victim of, or witnessed, another crime. And in an extremely minor way (the guy was caught, I think the victim will be fine once his cut ear heals, my friend is okay), this really made me understand how difficult it must be to be a witness in court. The simple pressure of the need for certainty must be enormously heavy. Holding onto that certainty is one thing by yourself, at home, and another one entirely once you step outside into a community that might not want you to be sure about what you'd seen, or onto a witness stand, where you're the target of someone whose job is to induce doubt.
I don't know that I'm ready to draw a larger conclusion from the incident yet. Maybe that it's pretty outrageously stupid to attempt a snatch-and-grab in broad daylight, where your flight direction is down a crowded escalator. But I found myself, once they apprehended the thief, trying to memorize as many details about him as I could, while I waited with my friend and the on-duty cop for more backup to show up: the teardrop tattoo under his right eye, the swirling gray pattern on his t-shirt, the red and black pattern on his shoes, the Spider-Man applique on his jacket. I won't have to be a witness in the case, I don't think: the on-duty cop has my friend's name if they need one other than the victim. But I just wanted to be sure about what I'd seen.
Update: R. Dave points out in comments that the cops could have caught the wrong guy. The person who was apprehended was identified by the victim, and was in possession of the victim's cell phone, which was subsequently returned to him. Just so I've got all the facts out here.