The jury in the murder trial of Mitchell Brooks got some more insight into the troubled marriage the accused had before his wife died.

Deena Brooks told several friends and colleagues she was afraid her husband would kill himself over their troubled marriage. On Monday, Deena’s best friend, Denise Parliament, testified.

"She was afraid Mitchell would shoot himself," Parliament says. She said Deena had expressed that concern when speaking about the guns Brooks kept in his workshop.

Parliament told the jury Deena wanted out of the marriage because she, “was tired of bending over backwards to try and please him and keep him from being angry all the time."

Parliament told the jury Brooks was on medication for depression and that Deena told her his emotions were back and forth after telling him she wanted a divorce.

"He was begging her to stay," and that Brooks had threatened Deena “to take her for everything financially."

Another co-worker Denna confided in testified on Monday. She told Deena multiple times not to go back to the house. However, Deena said she was fine.

Deena was shot to death in her home in New Lowell in 2013. Her husband has pleaded not guilty to first-degree murder.

The jury has heard testimony from several of Deena's friends and colleagues.

The defence has asked each witness if they knew Deena was having an affair. The answer has been no until Monday, when the defence asked Parliament

"You agree with me? Deena became involved in a relationship?” Parliament agreed.

She was then asked, “They had infect became intimately involved?" Parliament agreed again.

Parliament didn't say how long the affair was going on for, but did tell the court Deena would stay at her house several times and left to meet the man on the two occasions.

The defence is trying to suggest that Deena was never afraid Brooks would harm her, something most witnesses have conceded.