A minister drugged his wife, handcuffed her to the bed under the guise of spicing up their marriage, then smothered her with a pillow until she died, his ex-mistress testified Tuesday at his murder trial.

Vanessa Bulls said Matt Baker, then a Baptist preacher, had talked about killing his wife and making it look like a suicide. His wife, Kari Baker, had previously attempted suicide, Bulls said.

Bulls told jurors she did not help Baker plan the murder or participate in it, but she never reported it to authorities because she was afraid of exposing the affair that she said began about two months before Kari Baker's 2006 death. Bulls, 27, also said she was afraid of being arrested for knowing about Baker's plans but not stopping him.

Bulls said she understood "what he was capable of" but tried not to think about it as she continued seeing Baker for about three months after his wife's death. She said Baker told her he was happy with her so he would not harm her.

"He was and still is a manipulative liar who took me in my vulnerable state and made me believe everything he said," said Bulls, who has been granted immunity from prosecution.

Baker's attorney Guy James Gray told jurors last week that Kari Baker's death, initially ruled a suicide, only became a murder case after authorities found out about his affair. Baker, who faces up to life in prison if convicted, has maintained his wife committed suicide because of severe depression.

Under cross-examination, Gray asked about the account Bulls gave to several law enforcement authorities over the last four years, including some details that differed from her testimony Tuesday.

Bulls acknowledged that during those interviews she had repeatedly denied the affair and knowing anything about whether Baker killed his wife. She even said she "didn't tell the whole story" to the grand jury but didn't explain why or when she decided to do so.

"He's never going to admit guilt, even if he's found guilty," Bulls told jurors. "I'm setting things right."

Bulls said she met Baker in the fall of 2005 at church and that their affair began in February 2006 after he convinced her to have counseling sessions because of her divorce. She said Baker disparaged his wife, calling her a "fat bitch" and said she was a horrible mother to their two children because she was depressed about the death of their middle child to cancer.

"He said he wanted her out of his life," Bulls said, adding that Baker told her divorce was not an option because it would mean he could never preach again and he was concerned that Kari might fight for custody of their kids.

Bulls said Baker talked of various ways to kill his wife: a drive-by shooting, hanging her and making it appear to be suicide, and tampering with her car brakes. Once when Kari was late arriving home, Baker told Bulls that he "started getting excited that maybe she did have a wreck and he wouldn't have to do anything," the woman testified.

Baker even put drugs in his wife's milkshake one night but she complained that it tasted funny and didn't drink it, Bulls said. He also told Bulls that he ordered Chloroform online, Bulls told jurors. He obtained the prescription sleep aid Ambien secretly from his mother-in-law's house, Bulls said.

She said Baker decided to kill his wife on a night she was trying to spice up the marriage. Baker said he emptied the casings of sexual enhancement drugs he referred to as "horse pills" then refilled them with Ambien, Bulls testified. She said Baker told her that his wife took the pills, unaware that he had switched the medicine. He took the real pills.

Bulls said Baker handcuffed his wife to the bed, kissed her until she fell asleep and then kissed her forehead, telling her to give their deceased daughter a hug or kiss for him. Baker then smothered her with a pillow, but she gasped for breath, so he put his hand over the pillow directly over her nose until she died, Bulls testified.

According to Bulls, Baker said he then typed and printed a suicide note and rubbed Kari's hands on it in case authorities tested for fingerprints.

Bulls said she began to feel trapped with Baker because he said he was a preacher, so no one would believe her if she told. Then she broke up with him and urged him to turn himself in.

"He became irate. ... He said, 'I killed my wife for you and now you're leaving?"' Bulls told jurors.

She said about a month later, Baker called to ask how she was, in what she described as "the creepiest phone call of my life" because he sounded completely normal. She said she reiterated that she wanted nothing to do with him.

"He said, 'I miss you.' ... I said, 'You've got to turn yourself in.' He said, 'God has forgiven me."'

Bulls' testimony was to continue Tuesday afternoon.