The American Civil Liberties Union has brought a lawsuit demanding the release of video footage from a squad car dashboard camera from the day a St. Anthony police officer shot 32-year-old Philando Castile during a traffic stop earlier this year, the aftermath of which was live-streamed to millions of online viewers.

The suit, filed Thursday in Ramsey County District Court, comes amid an ongoing investigation by the state Bureau of Criminal Apprehension into the July 6 shooting during a traffic stop on Larpenteur Avenue in Falcon Heights, a suburb of St. Paul. The BCA, the state Department of Public Safety and the city of St. Anthony are all named as defendants in the suit.

“It’s troubling that under the circumstances of the Castile shooting, this otherwise public data is being purposefully withheld,” said Charles Samuelson, executive director of the state’s ACLU chapter.

Castile’s death sparked weeks of protests, including the takeover of the street outside the governor’s residence and the shutdown of Interstate 94, and reignited complaints of police brutality and insensitivity toward people of color. The aftermath of the shooting was captured in a grisly video by Castile’s girlfriend, who live-streamed it on Facebook where it was viewed and shared by millions.

The officer who fired the fatal shot, Jeronimo Yanez, was placed back on administrative leave after advocates protested the city’s decision to return him to street duty.

The suit alleges that the BCA is violating the state’s Data Practices Act by refusing to release the footage, which attorneys for the ACLU argued “may shed significant light on the 103 seconds between the time officers Yanez and [Joseph] Kauser exited their squad cars and the shooting death of Philando Castile.”

“The police killing of Philando Castile, following closely on the heels of the police killing of Jamar Clark in Minneapolis, has laid bare the broken relationship that exists between police in Minnesota and the communities they serve, particularly their relationship with people and communities of color,” the suit says. “Secrecy and lack of transparency has served to deepen the chasm between police and the community by reinforcing the community’s fear that police will not be held accountable for their acts of misconduct.”

The BCA has said the footage is “investigative data” that cannot be released until its probe has concluded.

The ACLU also sued for the release of all video associated with the death of Clark, an unarmed black man who was fatally shot during a confrontation with two white Minneapolis police officers last fall. The video was eventually released after Hennepin County Attorney Mike Freeman declined to charge the officers.