Due to the lapse in appropriations, Department of Justice websites will not be regularly updated. The Department’s essential law enforcement and national security functions will continue. Please refer to the Department of Justice’s contingency plan for more information.

You are here

Justice News

Department of Justice
U.S. Attorney’s Office
District of Columbia

Monday, December 4, 2017

District Man Sentenced to 20 Years in Prison for Slaying of His 81-Year-Old Mother

Defendant Attacked Mother With Fists, Wooden Stick, and Iron

            WASHINGTON – Derek Cook, 52, has been sentenced to 20 years in prison for killing his mother last summer at their apartment in Northeast Washington, announced U.S. Attorney Jessie K. Liu and Peter Newsham, Chief of the Metropolitan Police Department (MPD).


            Cook pled guilty in September 2017, in the Superior Court of the District of Columbia, to a charge of second-degree murder while armed. The plea, which was contingent upon the Court’s approval, called for an agreed-upon sentence of 20 years in prison. The Honorable Zoe Bush accepted the plea and sentenced the defendant on Dec. 1, 2017. Upon completion of his prison term, Cook will be placed on five years of supervised release.


            According to a proffer of facts submitted at the plea hearing, on the night of Aug. 12, 2017, Cook was having a conversation with his 81-year-old mother, Ann Alfredia Cook, in the bedroom of their apartment in the 5000 block of Fourth Street NE. Cook began to repeatedly strike his mother with a closed first, and she yelled for help. Cook also struck his mother repeatedly with a wooden stick and an iron, hitting her on various parts of her face and body. At the time of the beating, his mother was unarmed and in bed.


            The Metropolitan Police Department (MPD) arrived at the apartment at about 10:45 p.m., and Cook let them into the apartment building. However, he would not let police into the apartment. To gain entry, the police had to ram down the apartment door. After doing so, police found Ms. Cook, who was severely injured. She was taken to a hospital, where she died later that night. Derek Cook was arrested and has remained in custody ever since.


            In announcing the sentence, U.S. Attorney Liu and Chief Newsham commended the work of those who investigated the case from the Metropolitan Police Department. They also expressed appreciation for the efforts of Assistant U.S Attorney Thomas N. Saunders, who investigated and prosecuted the matter.

Violent Crime
Press Release Number: 
Updated December 4, 2017