Sen. Charles E. Grassley, who has been pushing for answers in the fatal November 2017 shooting of Bijan Ghaisar by two U.S. Park Police officers, again pressed authorities for information Tuesday. He was joined by Sen. Mark R. Warner in a letter to the FBI.

“The FBI’s slow pace and lack of transparency are weakening the trust between law enforcement and the communities they serve,” Grassley (R-Iowa) and Warner (D-Va.) wrote. The senators also sent a letter to the National Park Service, asking about use-of-force and pursuit policies, the status of the two officers and why their names were withheld for more than a year.

Warner also revealed Tuesday that he had first sent an inquiry to the FBI about the “lack of transparency from law enforcement” in the incident in January 2018, two months after the killing. He was joined by Sen. Tim Kaine and Rep. Don Beyer, both fellow Virginia Democrats, in a letter that was not previously released.

Nineteen months after Park Police officers Lucas Vinyard and Alejandro Amaya repeatedly shot the unarmed Ghaisar, who was slowly driving away from them in a Fairfax County, Va., neighborhood, no decision has been made on whether charges will be filed in the slaying. The FBI took over the investigation three days after the shooting, and the case is being handled by the civil rights division of the Justice Department and U.S. Attorney Jessie Liu of Washington.

In December, Grassley sent a letter to the FBI saying that “the Ghaisar family should not have to wait over a year to learn the facts of this case. Both his family and the public are entitled to a complete, credible, and independent accounting of the events surrounding the death of Mr. Ghaisar.” Grassley requested a copy of the FBI’s investigative report of the shooting and an update on the investigation within 11 days.

Three months later, FBI Assistant Director Jill C. Tyson sent Grassley a three-paragraph letter that said the investigation was ongoing and she could not reveal anything.

Fairfax County Police released video on Jan. 24 of U.S. Park Police chasing Bijan Ghaisar's vehicle on Nov. 17 and firing shots. Ghaisar, 25, later died.

Grassley quickly responded, asking why the FBI delayed its response, how many man-hours it had spent on the Ghaisar case since it began and how many hours in the previous 30 days. The senator also asked how many agents were assigned to the case. The FBI did not respond, Grassley wrote Tuesday.

“After 18 months, in which the FBI has offered virtually no updates or information, this case must be resolved for the good of the Ghaisar family and the public,” Grassley and Warner wrote. They requested a response to Grassley’s previous questions and an update on the investigation by July 2.

Publicly, Virginia’s two U.S. senators have been largely silent on the case. It was the Iowa Republican’s intervention in another Virginia case, the 2013 shooting of John Geer by a Fairfax County police officer, that sparked a sequence of events leading to the officer’s conviction, while Warner and Kaine stayed out of the case.

But Warner’s office released two letters Monday showing he and Kaine, along with Beyer, made an inquiry on behalf of the Ghaisars in January 2018. The three members of Congress asked FBI Director Christopher A. Wray why the family was not informed of the shooting for five hours, when the names of the officers would be released and why the Ghaisar family was mistreated during the 10 days the 25-year-old accountant spent on life support.

The FBI responded three months later that it would not discuss an active investigation. Then, in October 2018, Warner sent a letter to the acting director of the National Park Service, asking about the Park Police’s policy on body-worn and in-car cameras, about their policies on use of force and operating outside the national parks and about the number of Park Police shootings. The Park Police responded that it was studying cameras and did not answer the question about shootings by its officers, the letter shows.

No federal agents or officers wear body cameras or have in-car cameras, federal authorities said, and Vinyard and Amaya were not wearing them when they repeatedly attempted to stop Ghaisar on the George Washington Memorial Parkway on Nov. 17, 2017. Ghaisar had been involved in a fender bender minutes earlier on the parkway and drove away.

But a Fairfax County officer who followed the chase did capture it on his in-car camera, and Fairfax’s police chief, Col. Edwin C. Roessler Jr., released that footage, along with footage from a second Fairfax cruiser that had arrived on the scene. Fairfax officers then rendered aid to Ghaisar after Vinyard and Amaya fired nine times into his Jeep Grand Cherokee, Fairfax police said.

Vinyard and Amaya remain on administrative duty with pay, the Park Police said, and no internal investigation can begin until after a decision is made on criminal charges. Liu’s spokeswoman declined to comment Tuesday on when that might be. A spokeswoman for the FBI declined to comment on the letter from Grassley and Warner on Tuesday.

Vinyard’s and Amaya’s names were not released until March of this year, as part of the civil suit filed by Ghaisar’s parents in federal court in Alexandria, Va. Attorneys for the two officers said in court on June 7 that they were told by the Justice Department that a charging decision would be made within 20 days of that date.

“This investigation has moved from simply heartbreaking to an exercise in cruelty,” said Roy L. Austin Jr., one of the Ghaisars’ attorneys. “When a bipartisan set of U.S. senators have to repeatedly ask this government for basic information that would be provided in any other case, we are in uncharted waters. The family is deeply grateful to Senators Grassley and Warner for their efforts and all of the other help that they have received from members of Congress, but more than anything they simply want those who killed their son to be held accountable.”