Disabled Washington DC man, 64, is beaten to death 'by three girls aged 12 and 13, on street who were seen celebrating after', with youngest suspect later shot by masked assailant in her home

A 12-year-old girl was shot by a masked assailant in Washington, D.C., after she and two teen girls beat an elderly disabled man to death last fall. 

Reggie Brown of Northwest D.C. was 64-years-old when he was brutally beaten to death by the three girls, age 12 and 13, on Georgia Avenue in October. 

Horrific video seen by detectives showed the physically handicapped man being kicked and stomped on by the pre-teens.

Detective Harry Singleton testified on Friday that a man in a blue coat threw the 64-year-old to the ground and then the suspect along with the group of girls chased Brown as he tried to escape. 

After the 1am beating, the girls 'appeared to be in a celebratory mood' as they walked away from the scene of the crime. 

An autopsy determined that he died of blunt force trauma and was a homicide victim. 

'My uncle really didn't deserve this,' a niece of Brown's said in a statement to News4. 

'He was known in this community for years so for this to happen where he lived for 64 [years] is insane. They have to be held accountable!' 

Detective Singleton found no connection between Brown and the three girls, who are not being identified due to their ages. 

In a shocking twist of events, the 12-year-old girl linked to the crime was shot in her apartment on Friday at around 4am. Her Peabody Street apartment in the 500 block is only about a half-mile away from the scene of the brutal beating. 

The gunshot hit the girl in the leg and she was taken to hospital with non-life-threatening injuries. 

Police have not said whether the gunfire came from inside or outside of the apartment - but video of the scene shows a shattered pane of a first floor window.

A neighbor told News4 that they heard a loud bang and then saw two youngsters jump from a broken window and run down an alley.

Five months after the brutal beating of the 64-year-old disabled man, the three girls have been arrested in relation to Reggie Brown's death. 

On Friday, the 12-year-old and one of the 113-year-olds were charged with second-degree murder, the other 13-year-old was arrested and charged with second-degree murder on Thursday. 

Investigators took a number of young people into custody and several officers were seen using flashlights to inspect the scene before dawn. 

All three of the girls involved are resident of Northwest D.C. but it remains unclear how and if they knew Brown or how the detectives built their case against the pre-teens.