SAN DIEGO (CNS) - The wife of a Navy doctor fatally stabbed him as he slept, months after learning he was having an affair, a prosecutor said Wednesday in urging jurors to return a murder verdict, but a defense attorney said his client stabbed her husband out of rage and was guilty of voluntary manslaughter.

The jury began deliberating this afternoon in the trial of Jennifer Trayers, who is charged in the Dec. 4, 2010, death of her husband of 18 years, Dr. Frederick Trayers.

In her closing argument, prosecutor Fiona Khalil said the defendant lied and presented a "false concoction" when she told the jury how she killed her 41-year-old spouse.

Frustrated that he wouldn't talk to her about his affair, Trayers testified that she went into the bedroom with a butcher knife and asked him how to kill herself.

Trayers, 43, said she and her husband struggled over a sharper military knife that he pulled out, and she stabbed him in the back of the neck.

She said her husband stood up and pulled the covers off the bed, then she blacked out and couldn't remember stabbing him 10 more times, including two lethal stab wounds to the chest.

Khalil said the evidence didn't support the defendant's story. The prosecutor said Trayers attacked her husband in bed after he had taken sleep medication.

The victim was also stabbed eight times in the back and had cuts on his hands and arms.

"Dr. Trayers tried to save himself ... he could not. Fred Trayers was not able to stop her," Khalil told the jury.

Defense attorney Kerry Armstrong said his client attacked her husband in an "total uncontrollable rage," three months after finding out he was having an affair with a younger woman he met on a hospital ship.

Trayers found herself on an "emotional roller coaster" because her husband told her he would never leave her but at the same time was telling his mistress that he loved her and wanted a divorce.

The defendant installed spyware on her husband's computer and intercepted hundreds of emails between him and his girlfriend, talking about how they want to get married and have children, Armstrong said.

Jennifer and Frederick Trayers had no children.

"Think about how Mrs. Trayers must have felt when she read those things," Armstrong told the jury.

The day before he died, Frederick Trayers told his wife that he wanted to be more open in their relationship, Armstrong said.

When he wouldn't talk about it the next morning, the defendant said she tried to get her husband's attention by trying to kill herself. She said she grew more and more angry by the victim's response.

Khalil said Trayers sent an eight-page email to her husband's mistress the morning of the murder, telling the woman "My husband is NOT going to be yours" and "I was the last person he was with."

Trayers faces 26 years to life in prison if convicted of first-degree murder.