Updated

The mother of infamous Branch Davidian sect leader David Koresh has been stabbed to death, and Koresh's aunt was in custody on a murder charge Saturday.

Bonnie Clark Halderman, 60, was found Friday afternoon at the home of her sister, Beverly Clark, in a rural area near Chandler, Henderson County Sheriff Ray Nutt said. Chandler is about 175 miles north of Houston.

"It's still under investigation, and we really don't know what the motive was or what caused this to happen," Nutt said Saturday.

He said deputies were called to the home Friday and the two women were the only people in the house when deputies arrived. A knife believed to be the murder weapon was found.

Clark, 54, was being held without bail pending a court appearance. Jail officials said she did not yet have an attorney to speak for her.

Halderman wrote a 2007 autobiography, "Memories of the Branch Davidians: The Autobiography of David Koresh's Mother," that described how her son, Vernon Howell, became David Koresh, leader of the Branch Davidian cult.

In 1993, agents of the federal Bureau of Alcohol, Tobacco and Firearms tried to arrest Koresh for allegedly stockpiling weapons and explosives at the Branch Davidians' ranch compound outside Waco.

The confrontation led to a 51-day standoff that ended when the complex caught fire and burned to the ground on April 19, 1993, killing Koresh and nearly 80 of his followers.

About two dozen children were among the victims.

The government claimed the Davidians committed suicide by setting the fire and shooting themselves. Survivors said the blaze was started by tear gas rounds fired into the compound. A 10-month independent investigation concluded in 2000 that Koresh was solely to blame.