NYPD officer set to testify about killing of unarmed teen

FILE - In this June 13, 2012, file photo, police officers and supporters clap as Officer Richard Haste, center, exits the courthouse after posting bail in New York. Haste pleaded not guilty to manslaughter charges in the shooting death of unarmed, black teenager Ramarley Graham. Haste was expected to offer his first public account of the slaying at his department disciplinary trial on Friday, Jan. 20, 2017. Haste initially faced a criminal manslaughter charge in the 2012 death of Graham, but the case was ultimately dismissed. (AP Photo/Seth Wenig, File) (The Associated Press)

FILE - In this Feb. 18, 2012, file photo, Franclot Graham leans over his son, Ramarley Graham, in his casket before funeral services in the Bronx borough of New York. Officer Richard Haste initially faced a criminal manslaughter charge in the 2012 death of 18-year-old, Graham, but the case was ultimately dismissed. Haste was expected to offer his first public account of the slaying at his department disciplinary trial on Friday, Jan 20, 2017. (AP Photo/John Minchillo, File) (The Associated Press)

Political officials, civil rights activists and families of police shooting victims, join Constance Malcolm, center, mother of Ramarley Graham, and family members at a press conference outside police headquarters, Thursday Jan. 19, 2017, in New York. A disciplinary trial is underway for NYPD officer Richard Haste, who shot and killed the unarmed 18-year-old Graham in the bathroom of his New York City apartment. (AP Photo/Bebeto Matthews) (The Associated Press)