OAKLAND -- Rosie Murphy, the mother of a man facing death row for murdering three people and a dog, has been described by family members and former neighbors as a selfish parent who verbally abused her then-preteen children and forced them to sell drugs on the streets of East Oakland.

A son, her former husband and a niece all testified that Murphy spent government child support payments on herself, called her children using curse words and, at one point, told police drugs found at her house belonged to her children not her.

As one neighbor put it, "She was a very mean lady."

On Wednesday, Murphy appeared in court against her will to testify at the penalty phase in the trial of her son, convicted triple murderer David Mills. Defense attorneys have portrayed Murphy as culpable in the crime-filled life that her 37-year-old son led.

Wearing sunglasses and sitting in a wheelchair, the 63-year-old Murphy vehemently denied ever forcing her children into the drug trade and said she felt "zero" responsibility for her son's fate.

"That's one thing I never did, never did," she said at one point. "I'll go to my grave, I did not have one of my kids sell drugs, I'll take a lie detector."

Murphy, who was arrested and forced to testify after she ignored a subpoena, called all previous witnesses who told horrific stories about her liars and disputed that she was a drug addict even though medical records show she was once treated with

"That's the biggest lie that has ever jumped off in here," Murphy said at one point. "That's a lie, sure enough."

Murphy remained combative throughout questioning from her son's attorney and said she did not want to cooperate with the defense team because its attorneys had questioned other family members about her child-raising practices.

Mills' defense attorney, William Linehan, has provided, through witnesses, a troubling, and at times, an unfathomable description of his client's childhood in an attempt to convince the jury that Mills should be sent to prison for life and not death row.

While Linehan has said Mills' troubled life is not an excuse for murdering three people, he also has said the jury should consider the circumstances as it makes its decision.

Linehan has said the jury should also consider how Mills, despite not receiving any kind of parenting, has successfully pushed three children toward educated lives. Mills' son, daughter and a stepdaughter are all currently enrolled in college.

All three also testified, portraying Mills as father who, from jail, would demand excellence in school and warn them against making the same dangerous mistakes he has made in his life.

"All he wants for me is for me to have a better life than he had," said his daughter, Theresa Barnes, 19. "He's tried his best and he is the only reason, I swear to God, that I am in school right now."