ST. LOUIS – A 16-year-old is in custody in connection with a mass shooting in downtown St. Louis that left one teenager dead and 11 other people injured.

The shooting took place just before 1 a.m. on June 19, at a party on the fifth floor of an office building near Washington Avenue and 14th Street. Investigators with the St. Louis Metropolitan Police Department said the event was organized on social media.

Eleven teenagers between the ages of 15 and 19 were shot. One of the victims, 17-year-old Makao Moore, died. A 17-year-old girl was trampled while fleeing from the scene and suffered minor injuries.

In the hours after the shooting, police said the party was by invite only and officers are investigating how the teens gained access to the building.

Evita Caldwell, a police spokeswoman, said last month that two teenagers had been arrested since the gunfire. However, they were released by Juvenile Court and detectives were asked to investigate more.

On June 23, the department released a photo asking for the public’s help to identify five different teenagers. Caldwell said had the teens’ names.

The 16-year-old suspect was taken into custody Tuesday in Bellefontaine Neighbors, with the assistance of the local police department.

The teen was brought to the St. Louis County Juvenile Detention Facility and charged with first-degree assault.

St. Louis police are asking anyone with information on the party or shooting to contact them directly at 314-444-5371. If you wish to remain anonymous or are interested in a cash reward, call CrimeStoppers at 866-371-8477.

This is a developing story and is being updated. Please refresh this story every few minutes.