A Virginia family is demanding answers after United States Park Police killed Bijan Ghaisar last month.

It has been 27 days since he died and there are still unanswered questions such as 'what caused officers to shoot the 25-year-old.'

“Every year on Christmas Eve my family went to the national Christmas tree,” Negeen Ghaisar said.

However, the Ghaisar family spent part of their day at the US Park Police station insisting on more information this year.

Bijan Ghaisar's loved ones broke down in tears while holding three signs with one message.

“We need answers for who (and) what happened to our son,” Kelly Ghaisar told WUSA9.

Officers shot Ghaisar on November 17th after a police chase down GW Parkway.

Park Police said Ghaisar took off from a crash scene that night.

A police spokesperson said Ghaisar never shot at officers, but it is not clear if police shot him before or after he wrecked his car several miles away.

“I want to know who shot my brother. I want the officers' names,” Negeen Ghaisar stated.

Two park police officers involved in the shooting were placed on administrative leave, but their names have not been released.

A Fairfax County policeman who joined the chase captured the shooting on his in-car camera.

The video was turned over to the FBI because it is now handling the investigation.

“We don't know who did it,” Kouros Emami said. “They're at home hanging out with their family, but we're here in pain.”

“We miss you Bijan. We love you,” Kelly Ghaisar said.

“We love you so much. The whole world loves him,” James Ghaisar added.

Ghaisar's family said he was not known to carry weapons, but neither park police nor the FBI has said if the 25-year-old was armed

“Many details of what lead up to this shooting remained a mystery on Christmas Eve as police stayed tight-lipped during their investigation.

The FBI has not released a timeline on its investigation or when video from that night may be released to the public.