By Harriet Ryan
Court TV

NEW BRUNSWICK, N.J. — A physician who was having an affair with Melanie McGuire when her husband was killed testified Wednesday that he and McGuire, a nurse at his fertility clinic, were in love and planned to eventually leave their spouses and start a new life together.

"She was going to divorce Bill. Then a little later, I was going to divorce Charla. The two of us would get married, buy a house and have children," Dr. Bradley Miller told jurors at McGuire's first-degree murder trial.

He said the plan was unexpectedly sidetracked on April 28, 2004, when McGuire's husband, William, was able to raise enough money to close on a house for the family, something Melanie McGuire had doubted his ability to do.

Miller testified that he was angry at hearing the news and yelled at McGuire, asking, "Why do you want to buy a half-million-dollar house if you ultimately want to get a divorce from Bill?"

Later, he said, she called him with a terse message.

"She just said, 'Don't worry. Everything is going to be fine,'" he said.

William McGuire was not seen alive again. Prosecutors contend McGuire, 34, sedated her husband and shot him that night and later dismembered his body and tossed it in the Chesapeake Bay. McGuire's defense maintains that the victim moved out that night after a bitter fight and was killed by someone else, perhaps because of alleged gambling debts.

Miller, once considered a suspect in the murder, spent four hours on the witness stand Wednesday recounting conversations with McGuire that took place before and after the killing. He is expected to complete his testimony Thursday.

The reproductive endocrinologist was never asked directly whether he had come to believe McGuire was responsible for William McGuire's murder, but he seemed to suggest his opinion had shifted from an initial position of innocence in an answer to a prosecutor's question about his mindset in an early police interview.

"I was still very much in love with her and I still believed she had nothing to do with this," he said.

Miller provided the most detailed testimony in the trial thus far about McGuire's state of mind on the night prosecutors say she killed her husband. He said that after her brief, reassuring phone call April 28, she phoned again and said that her husband had fallen asleep, but when he woke up, she was going to ask him for a divorce. He said she promised to call him in the morning and hung up.

When they spoke the next morning, he said, she was upset and asked him to write her a prescription for the anti-anxiety medication Xanax, which he did. She said her conversation with her husband had devolved into a fight, and that William McGuire had struck her and forced a dryer sheet in her mouth. He said she spoke of getting a restraining order and filing for divorce.

Miller said that during this time McGuire concealed several pieces of information from him, including the purchase of a gun the same caliber as the murder weapon and a series of long car trips prosecutors have said are connected to the murder.

He said that although it was not unusual for them to speak 20 times a day and even share details of their children's bedtime routine, McGuire never mentioned buying a gun two days before her husband vanished. He said she told him about the gun months later, saying she got it for her husband, who wanted it for protection at their new rural home.

Miller also said she delayed telling him that she had traveled to Atlantic City three times after William McGuire went missing. McGuire's car was discovered there, and Melanie McGuire said she had moved the vehicle to play a prank on him and returned twice to see if it was in the same spot.

Similarly, he said, she neglected to tell him that she had gone to Delaware on May 4, the day before McGuire's remains were found in the bay. He said she told him she went to buy furniture there because the state had no sales tax.