(RNS) — A Catholic social justice activist who was knocked to the ground by police during a protest over racism last year has sued the city of Buffalo, its mayor, the police commissioner and several police officers.

The lawsuit, filed by Martin Gugino on Monday (Feb. 22) in U.S. District Court for the Western District of New York, alleges Gugino’s constitutional rights to peaceful assembly were violated.

Gugino, who fractured his skull and suffered a brain injury, accuses the city of an “unconstitutional and draconian” curfew that was “selectively enforced against peaceful protesters.” It accuses the city of “unreasonable use of force” to disperse the protesters, a failure to train and supervise officers and a “deliberate indifference” to constitutional rights, according to the civil suit.

Ten days ago, a grand jury declined to indict Buffalo police officers Aaron Torgalski and Robert McCabe on criminal felony assault charges. The two officers remain suspended pending the results of an internal investigation into the case.

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In a video of the June 4 confrontation, Gugino was seen approaching police who were in riot gear during a demonstration over the death of George Floyd. Two officers — McCabe and Torgalski — pushed Gugino away. He fell back, cracking his head open and visibly bleeding on the sidewalk as the police officers walked past him.

The video went viral and became symbolic of the kinds of police action that have sparked calls for fundamental reforms to American policing.

Gugino, who is now 76, ended up in intensive care and spent nearly a month at Erie County Medical Center. He is now living on his own in Buffalo, but he lost hearing in one ear and still is unstable while walking.

He remains staunchly committed to nonviolent protest and likes to point to the clause in the First Amendment that speaks of “the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.”

Richard Weisbeck, a lawyer for Lipsitz Green Scime Cambria who filed the suit, said in a statement that “Gugino became the victim of police brutality at the very moment he was peaceably and constitutionally protesting against police brutality.”

The suit asks for compensatory and punitive damages in an amount to be determined at trial.