The sister of a 27-year-old man fatally shot by a Chicago Police officer last summer in the Greater Grand Crossing neighborhood on the South Side has filed a federal lawsuit against the city.

Martice Milliner died at Jackson Park Hospital after the shooting that happened about 11:30 p.m. on July 9, 2015, in the 7500 block of South Langley, according to police and the Cook County medical examiner’s office.

Police said at the time that the officer opened fire after Milliner pointed a gun at him. Khadija Farmer says her brother was at a birthday celebration and that the officer shot him “without cause or provocation,” according to the suit filed Thursday in U.S. District Court.

The suit lists the city as defendant, along with the officer who shot him and an unknown number of other officers “who jointly agreed and/or conspired with one another to prepare false, misleading and incomplete official reports” to justify the shooting, the suit alleges.

A city law department spokesman declined to comment Friday evening.

The Independent Police Review Authority’s investigation of the shooting is ongoing.

According to police reports posted on IPRA’s website, police had been called to a report of a person with a gun on the block. Milliner matched the description, and when officers tried to stop him, he reached for a gun in his waistband, police said.

The officer, “fearing he would be shot,” opened fire, the report says. Milliner still refused to drop the gun after he was shot, so the officer shot him again, police allege.

Milliner, of the 9100 block of South Green Street, was pronounced dead at 12:41 a.m. on July 10, 2015 at Jackson Park Hospital, according to the medical examiner’s office. An autopsy ruled he died of multiple gunshot wounds in a homicide.

No officers were hurt. Police said they recovered a weapon at the scene.

Farmer claims police made up the story “to cover up their misconduct,” according to the nine-count suit, which seeks an unspecified amount in punitive damages.

Milliner was one of two people shot by Chicago Police officers in 24 hours from July 9-10, 2015.