Police said an anonymous tip may have saved many lives at a protest rally at Miller Park on Monday.
Police were tipped off around 11:30 p.m. that a black male wearing jeans, a dark shirt and a camouflage tactical vest had been seen leaving the Douglas Heights apartments with an AR-15 semi-automatic rifle.
The man was seen on a Real Time Intelligence Center camera holding an orange sign and walking toward Miller Park.
A man who matched the description was spotted walking at the north end of the park.
An officer approached the man and asked to speak with him, but he kept walking away.
The officer caught up and grabbed his right hand. The man pulled away, but other officers helped get him in handcuffs.
He was identified as Trevan Young, 29, of the Laurel Ridge Apartments, 4715 Bonny Oaks Dr.
Police said he had three AR-15 magazines, two of which were easily accessible to him. The magazines contained .223 rounds. He also had an AR-15 rifle in the backpack he was wearing. It was broken down at the time.
He was arrested for unlawful possession of a weapon, disorderly conduct, and resisting arrest.