FORT WORTH, Texas (AP) — An arrest affidavit says a Fort Worth man charged with murder in the death of his mother told investigators that he smothered the 85-year-old woman with duct tape and his hand.

The Fort Worth Star-Telegram ( ) reports that 50-year-old Kenneth Edward Baker indicated to homicide detectives that he killed Margaret Shelton on Aug. 31 because she was belligerent and accusatory. Police say the woman had the onset of dementia or Alzheimer's.

Homicide Detective E.C. Pate says, "The victim fought and resisted his efforts to kill her."

Baker remained in the Tarrant County Jail Tuesday in lieu of $250,000 bail. Jail records did not list an attorney for him.

Baker had called 911 on the afternoon of Aug. 31, telling dispatchers that he had killed his mother.