The Justice Department won't seek federal criminal civil rights charges against U.S. Park Police officers who shot and killed 25-year-old Bijan Ghaisar two years ago on the George Washington Parkway.

The unarmed Ghaisar died 10 days after being shot multiple times by officers Lucas Vinyard and Alejandro Amaya Nov. 17, 2017. Dashcam video released by local police shows Ghaisar leading officers on a four-minute, stop-and-go chase on the GW Parkway. Twice during the chase, which was precipitated by Ghaisar's involvement in a fender-bender, Ghaisar stopped, but then resumed driving when officers approached with guns drawn.

The chase continued onto a side street, and officers again approached with guns drawn when Ghaisar stopped a third time. When Ghaisar again started to drive off and attempted to maneuver past the officers, they fired nine shots, and the video shows Ghaisar's car slowly rolling into a ditch.

"We, along with everyone else who has seen the shocking video footage, watched two U.S. Park Police officers gun down our unarmed son and brother at close range on the side of the road," Ghaisar's family said in a statement.

The Justice Department said it could not prove beyond a reasonable doubt the officers willfully broke federal laws and was unable to disprove their self-defense claims.

Ghaisar's family said it will continue to seek the prosecution of officers Vinyard and Amaya.

"Two people executed an American citizen who they were sworn to protect and serve, and the only reason they’re escaping justice is because they wear badges," the family said.

Hundreds of people are expected to gather at the Lincoln Memorial at 3 p.m. Sunday to commemorate the second anniversary of the shooting.

Park Police said it is reviewing the FBI's findings.

"In the interest of objectivity and impartiality, the USPP transferred the case to the FBI in November 2017," Park Police said in a statement. "The decision announced today was the result of an extensive and independent investigation by the FBI. Any loss of life is tragic, and the loss of Bijan Ghaisar has impacted many people, including his family, friends and our community.

Park Police and the FBI have faced criticism from members of Congress, including Sen. Charles Grassley, R-Iowa, and Rep. Don Beyer, D-Va., for dragging their feet on the investigation and for a lack of transparency. Fairfax County Police released the dashcam video on their own after first asking the FBI to do so in a timely manner.

“For two years the FBI, Justice Department, Department of the Interior and U.S. Park Police have refused to answer the question, ‘Why did Bijan Ghaisar die?’" Beyer said in a statement. It beggars belief that these agencies could conduct the longest and least transparent of investigations and somehow leave that question even more obscured than it was when they started.

“I am not satisfied by the Justice Department’s statement and I do not believe my colleagues will be either. This will not end here.”

“The Ghaisars deserve to understand what happened to Bijan," U.S. Sens. Grassley and Mark Warner, D-Va., said in a statement. "To that end, we will be formally requesting a briefing within the next 30 days from the Department of Justice to understand what went into the decision not to pursue charges in this case. We will continue to closely follow this case, including whether state or local charges are filed, or an internal affairs investigation is opened.”