According to multiple accounts, an event at Trevino Paint reportedly drew far more attendees than the venue could accommodate, leading crowds to flood into the surrounding area. Trevino is a paint-and-sip studio and event venue in the Alley Shops area that hosts private parties, birthdays, teen events, and other gatherings.

Witnesses described teenagers blocking traffic, running into the street, dancing on columns, and filling nearby parking lots.

One resident said the crowd size appeared to double within just 20 minutes during a brief drive up and down Reisterstown Road. By the time they returned, police officers were already on scene attempting to manage the situation.