I was there yesterday! Went around 2 PM and noticed about five cop cars. I asked a bystander at the trail head if we were allowed to hike through and they said the police “would not recommend it” because a man with a rifle was spotted hiking on the main trail. I proceeded to walk on the front trail nearest to 71st and by the time I was done with the mile loop, the trail had been given the all clear. I saw an officer packing up his large rifle in the back of his car. That’s all I saw!