MAYVILLE — A Jamestown man accused of shooting and killing his wife last year pleaded guilty to a lesser charge of first-degree manslaughter on Thursday, moments before his trial was set to begin.

Keith L. Robbins is facing a sentence of 20-25 years with five years of post-sentence supervision when he is sentenced later this year.

Robbins was accused of killing his estranged wife, 36-year-old Shari Robbins, in a Prospect Street parking lot on Nov. 10, 2016, in Jamestown. Robbins was taken into custody on Nov. 15, 2016, after a six-hour standoff not far from where the shooting took place.

The murder trial was set to begin Thursday morning in Chautauqua County Court after a week of jury selection but was quickly adjourned after Robbins agreed to a plea deal with the District Attorney’s Office. With the plea deal, Robbins waived his rights to appeal the trial and his right to a jury.

Robbins, who was 36 at the time of his arrest, avoided the possibility of being found guilty of second-degree murder, a Class A felony, and a 25-to-life sentence. Both District Attorney Patrick Swanson and Public Defender Ned Barone agreed the plea was the right choice to make.

County Court Judge David Foley accepted Robbins guilty plea after reading him his rights.

Swanson said the family of Shari Robbins was comfortable with the sentence.

“He waived his right to appeal, which means essentially that he’ll be spending the next 20-25 years in prison, which is an appropriate sentence given the conduct,” Swanson told The Post-Journal.

The district attorney felt the reduced sentence was appropriate and fair.

“We had lengthy discussions with the family and explained (the reduced sentence) to them and they understood,” Swanson said. “I think we’re all pleased with the disposition and we’ll be arguing at sentence for the full 25 (years).”

Swanson and Barone both said the plea deal would help avoid extending the trial through the coming weeks and give closure to both families. Both said they didn’t want Robbins’ two children to endure the continuous publicity of the trial.

“I think there’s some positive to that,” Swanson said.

Swanson said if his office had pushed for the second-degree murder sentence, there was no guarantee Robbins would have received the maximum sentence.

“There’s no 100 percent certainty that he would have gotten more time than he did,” Swanson said. “There was the hope that we could get a 25-to-life sentence but there’s no guarantees at trial and the finality with him waiving his (right to) appeal is important to us.”

While the District Attorney’s Office will be pushing for the maximum 25 years, Barone said he will be asking the court for the lesser 20-year sentence.

“Well, I think that in this particular case it’s a good plea, it’s a good resolution,” Barone said. “I think that it takes into consideration a number of different factors that were relevant in this specific case.”

Those factors included Robbins’ defense that he was under extreme emotional disturbance and did not intend to kill his estranged wife.

“There was a period of time that Mr. Robbins was suffering from some emotional issues which resulted, unfortunately, in the death of Shari Robbins,” Barone said. “We’ve maintained from the beginning that (Keith Robbins) never actually intended on murdering her and therefore that’s how we came up with the plea.”

Barone said the extreme emotional disturbance defense, similar to the “in the heat of the moment” defense, deals with a period of time an individual is experiencing mental health issues, depression and stress all at once that causes an individual to act in way they normally would not have. He said this defense doesn’t pardon an individual of responsibility but it mitigates the damages.

“That’s why we’re comfortable with the ultimate plea,” Barone said. “We think it’s a very good result and we’re happy with it.”

Barone said his legal team was prepared to begin the trial on Thursday and was surprised the plea deal was finalized so quickly.

Robbins will be formally sentenced Dec. 18.