In this case it was a homicide suspect who was trying to escape through the park. I was asked the same thing, and I did happen to see the guy (he was running off the trail along the parkway wall) and the guy was a black man with dreads.

Edit, more specifically wearing a forest green hoodie and grey pants.

I saw the guy as I was leaving the park; he was running parallel to the parkway toward the tunnel opposite the trail. Three cops came running by a minute later, guns drawn, and I heard on their radio that he was armed apparently. Kinda scary, I didn't know what was up but the guy did stop and we stared at each other for a minute.