Exactly one year ago today, Officer Richard Haste fatally shot unarmed 18-year-old Ramarley Graham in his Bronx apartment. Several months later, Haste pleaded not guilty to first- and second-degree manslaughter charges in the teen's death. To mark the anniversary, Graham's family has filed a lawsuit against the NYPD in which they claim that after shooting Graham, Haste threatened to shoot Graham's sobbing grandmother, then took her in for hours of intimidating and questioning.

The teen was killed on February 2nd, 2012 after Haste and other officers allegedly observed him buying drugs and followed him to his Bronx home. Haste could be seen on surveillance footage with other officers as they attempt to kick open the door to the Graham residence. After they gained entry, Haste ran upstairs and found Graham in his bathroom. The officer allegedly yelled, "Show me your hands! Gun! Gun!" before shooting Graham once and killing him. The teenager was unarmed, and had been dumping a small amount of marijuana into the toilet.

According to the lawsuit, Graham's grandmother, Patricia Hartley, was feet away from Graham at the time, and immediately cried out, "Why did you shoot him, why you killed him?" Haste then allegedly pushed Hartley into a vase and said, "Get the f--- away before I have to shoot you, too."

Hartley—who was 58 and weighed 85 pounds at the time—had her arm twisted behind her back by Haste after she tried to make a phone call. She was then taken to the 47th Precinct station house, where investigators allegedly called her a "f---ing liar" and claimed she was covering for the dead teen, whom cops believed had thrown a gun out a window.

During the interrogation, officers allegedly showed her a photo of a shot man they claimed was her grandson. They also allegedly dipped their hands into her coffee, then flicked their fingers against a wall to show how blood splatters. Hartley was kept at the station for seven hours altogether. You can see a 13-minute interview with the parents of Graham discussing the case:

The lawsuit, which names the NYPD, Haste, Commissioner Ray Kelly and other officers, accuses the NYPD of improperly training officers, unfairly targeting minorities in stop-and-frisks and trying to cover up the shooting. To the last point, the NYPD initially claimed Haste and Graham had struggled with one another and the cop's 9 mm handgun discharged, which has since been disproven. The lawsuit claims the account was false and "made with the intent to conspire to cover-up the true facts of the incident."

Also to mark the anniversary, a vigil and rally are planned for today in the Bronx; family, friends and neighbors will march to the 47th Precinct station house.