UPDATE:Police have added murder in the second degree to the charges against Bahsid McLean.
McLean and Harris were arraigned on Thursday, and are being held without bail. They will both appear in court again on Monday.
McLean is accused of murdering his mother, Tanya Byrd, and then dismembering her and disposing of her body.
Law enforcement sources previously said that McLean insisted his friend William Harris killed Byrd. McLean reportedly told police that Harris threatened his life and the life of his younger brother if McLean didn't help him dispose of the body.
Harris reportedly told police that McLean showed him cell phone photos of Byrd's dead body on the way to school Monday morning, and asked his help disposing of the body. Police also recovered a photo from McLean's cell phone depicting him holding up his mother's severed head.
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Both Harris and McLean owned up to dismembering and disposing of the body, law enforcement sources said.
Metro's original story is below.
Cops have arrested and officially charged the son of the woman found killed and hacked to pieces in the Bronx yesterday, as well as a friend he named as an accomplice.
Police confirmed the identity of the victim as Tanya Byrd last night, after several hours of questioning her son, Bahsid McLean.
McLean and the friend, William Harris, have both been charged with "unlawful dissection of a human body."
Neither McLean nor Harris has been charged with murder.
McLean reportedly made a partial confession to police, according to a law enforcement source, telling police he helped dismember and dispose of his mother's body, but that Harris was the killer.
Initial investigations at Byrd's apartment, which police said smelled strongly of bleach, turned up an empty box from an electric saw, and evidence of a missing shower curtain that matched the one the torso of the victim was wrapped in.
Investigators later found surveillance camera footage showing two men, one the same height as McLean, exiting the elevator of Byrd's building into the lobby with several bags and pieces of luggage. The two men were joined by a third man in the video, according to police reports. The trio apparently put the various bags in a shopping cart and wheeled it out of view.
A law enforcement source reported that police located Harris by tracking Byrd's cell phone. Harris' confession mirrored McLean's: Harris reportedly told police that he only helped McLean dismember the body. McLean murdered his mother before Harris even arrived at the apartment, Harris reportedly said.
McLean told police that Harris killed Byrd because she was critical of him for selling marijuana, a law enforcement source said. One of the charges against Harris is possession of marijuana.
Follow Danielle Tcholakian on Twitter @danielleiat