West Palm Beach Police say 26-year-old Trevonte Adderly hit Delores Allen in the face and set the living room on fire in July. Police say she died Friday. Adderly was arrested two days later and remains in jail without bond.
Family members say he had been living with his grandparents and that there had been several violent conflicts before the July incident.
But U.S. Navy officer Travon Marq Adderly told the Palm Beach Post his brother suffers from severe mental illness and needs to be hospitalized. He says his brother has struggled with mental health since watching their father kill their mother in 1997.
The Baltimore Ravens' Willie Snead and the team's owner donated money to help the family.
Information from: The Palm Beach (Fla.) Post, http://www.pbpost.com
Copyright 2019 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.