MARTINEZ -- Susan Polk spoke of how she would kill her husband long before he died -- by drugging him, shooting him, drowning him or running him down with a car, a prosecutor told jurors Tuesday at the woman's first-degree murder trial.

The defense contends they both had threatened each other and that she had long lived the life of a battered woman under Felix Polk's physical and emotional control, bound to a marriage born from rape.

"You will see that the defendant is nothing but a cold, calculated, callous murderer," prosecutor Tom O'Connor said during opening statements Tuesday.

Susan Polk, 47, is accused of stabbing to death her husband, Felix, 70, in October 2002 at the couple's home in the upscale San Francisco suburb of Orinda. She claims that Felix attacked her with a knife, and that she defended herself.

Prosecutors allege she killed for his multimillion dollar estate.

Defense attorneys argue that Susan Polk's life hit the skids as a teenager when she began seeing the then 42-year-old -- and married -- Felix Polk as a therapist. He was a well-known Berkeley psychologist. She says they started having sex when she was 16, after he drugged and raped her.

The couple eventually married and had three sons -- Gabriel is now 18, Eli is 20, and Adam, 22.

Since Felix's death, the family members have turned on each other. Gabriel and Adam will testify for the prosecution, and have filed a wrongful death lawsuit against their mother. Eli will be his mother's main defender.

Gabriel will testify his mother often threatened to kill his father, O'Connor told jurors.

"She had openly talked to him (Gabriel) about killing his father for well over a year before his death," O'Connor said.

Susan Polk had gone to Montana for a time, seeking to relocate after she filed for divorce. She returned home on Oct. 13, 2002, she says, to collect her things.

In her absence, Felix had won a court order giving him the house and custody of Gabriel.

It was about 11 p.m. when Susan confronted Felix in a cottage on the property.

"He came at me ... and the next thing I knew he was stabbing at me with a knife," she told The Associated Press in a jailhouse interview before the trial.

The couple struggled. Susan grabbed the blade.

"I stabbed him in the side with it," she said.

Felix fell limp on the floor. Susan left his body there for 24 hours until Gabriel discovered it the next night. She initially denied involvement and later changed her story to self defense.

"Gabriel Polk found his father's motionless body covered in blood," O'Connor said, describing Felix as "a man fighting for his life."

The coroner's report showed five stab wounds to his chest and stomach, and defensive injuries on his hands and feet -- 27 wounds in all. Strands of Susan Polk's hair were found gripped in his hand.

Defense attorneys will try to show that Felix had a history of violence and mental illness. He was hospitalized for more than a year while in the Navy in 1955, diagnosed with schizophrenia after a suicide attempt. He was off his medication at the time of the killing, according to defense attorneys.

"Susan Polk defended herself against an attack by a rageful, brutal, aggressive man," defense attorney Daniel Horowitz told jurors, explaining that it could have been "Susan lying on the ground covered in blood."

"This man had a chronic lifetime illness that led him to have outbursts of rage, violence and anger," Horowitz said.

He flashed pictures of Felix Polk's bloodied face and body on a white screen, explaining that none of the wounds were "killing" stabs, that Susan swung the blade wildly to fend of the attack.

She was the victim, he said.

Horowitz described Felix as a delusional man who would lecture at child abuse conferences of his oldest son's kidnapping and rape by a satanic cult when he was just 2 years old.

Horowitz said no such abuses were ever proved, and Adam denies having been kidnapped.

"My mind is so heavy with wretchedness, with utter loneliness, with an unknown past, a frightening future and an intolerable present that no choice remains," Felix wrote in his 1955 suicide note, obtained by The Associated Press along with medical records.

Horowitz claims Felix found himself in the same place when Susan filed for divorce and threatened to tell his friends and neighbors how they met, that he took advantage of a young patient. It would have ruined him.

His final act, Horowitz theorizes, was to kill Susan, then himself.

Susan Polk cried and wiped tears from her eyes throughout opening statements, shaking her head and scribbling notes.