Multiple police departments responded to a shooting that left one dead at an apartment complex in Arapahoe County on Tuesday evening.

The Arapahoe County Sheriff’s Office — along with the Aurora Police Department, Denver Police Department and South Metro Fire Rescue — responded to a shooting report at the Ivy Crossing Apartment complex in the 2300 block of South Quebec Street around 9:30 p.m., according to a news release by the sheriff’s office.

A 23-year-old man was found injured outside of the apartments with around 50 people crowding the area. The man was taken to a nearby hospital, where he later died from his injuries.

Witnesses reported that there was a group of people yelling and fighting outside before the shots were fired, according to the sheriff’s office.

A group of at least four armed men in black outfits and masks fled the scene.

The police departments searched for the suspects, but did not find them.

“This is believed to be an isolated incident,” the sheriff’s office said on Wednesday morning.

On Aug. 21, six people were arrested at the same apartment complex by the sheriff’s office during “proactive policing.” Four of the six were thought to have ties to the Venezuelan gang Tren de Aragua (TDA).

Officers seized 750 counterfeit pills, ketamine and a stolen car during the multiple arrests.

The department declined to identify the suspects or specify how they are connected to the gang due to ongoing investigations, Deputy John Bartmann, a spokesperson for the sheriff’s office, told The Denver Gazette.

The “proactive” policing at the complex was not due to reported gang activity but because of an increase in crime in the area, according to the department.

During a “proactive” policing situation, the sheriff’s office will send officers to an area of statistically high crime.

Crime has been above average in the area for “some time,” according to Bartmann. He noted that it was that way when he left street duty as a deputy in 2008.