Authorities are searching for former NFL player Sergio Brown after his 73-year-old mother’s body was found Saturday evening in a creek less than 100 yards from her home.

Officers found Myrtle Brown’s body, and a medical examiner determined Sunday that she had been injured during an assault.

Relatives told officers Saturday in Maywood that they could not find Sergio Brown, 35, or Myrtle Brown, police said.

Sergio Brown played defensive back from 2010 through 2016 with the New England Patriots, Indianapolis Colts, Jacksonville Jaguars and Buffalo Bills.

On Sunday, the Cook County Medical Examiner’s Office identified her cause of death as multiple injuries from assault.

Carlos Cortez, a neighbor of Myrtle Brown, told CBS News he last saw the two in person Thursday. And he said police saw something else on his Ring doorbell camera.

“They seen him taking out the trash, and they seen him have a bonfire where he burned all her clothes,” he said.

The Associated Press contributed to this report.