NASHVILLE, Tenn. (WKRN) — A man beat his teenage brother to death at a home in Nashville, while their mother watched and did nothing to stop it, an arrest warrant alleges.

Rebecca Greenwood, 52, and David Matheny, 33, were arrested and booked into the Metro jail Saturday morning on charges of criminal homicide.

Metro police said they responded Friday afternoon to a residence on Topeka Drive in the Hermitage neighborhood, where a 14-year-old boy had reportedly been found unconscious. He was pronounced dead by first responders.

An arrest warrant states officers spoke with Greenwood, who claimed her 14-year-old son had fallen in the shower the day before and had hit his head. She said she and Matheny, her older son, checked on the teenager multiple times that day, then went to a bar for drinks and checked on him again before going to bed that night, according to the paperwork.

Greenwood explained she and Matheny went to the grocery store the next day to buy cleaning supplies and get fast food, police said. She stated they cleaned the residence, then went to check on the 14-year-old, who they found unconscious, so they called for help.

The 14-year-old boy was pronounced dead at the residence. Upon further investigation, police determined the teenager’s injuries were not entirely consistent with a fall.

Detectives questioned Greenwood, who they said admitted she had watched as Matheny punched the teenager and “stomped on his head” during an altercation. She explained she told Matheny to stop, but walked away without making sure the attack had ended, according to police.

Officers added the mother and son cleaned the residence to get rid of evidence of the attack, so they were each charged with one count of evidence tampering.

Greenwood was also charged with child neglect, while Matheny was charged with child abuse. No bond was set for either suspect on the criminal homicide charges.

The booking photos for Greenwood and Matheny were not immediately released by Metro police.