The man accused of shooting and killing his mother and 12-year-old brother was sentenced to 48 years in prison with no possibility of early release.

Regis Mister, a former Yalobusha County Sheriff’s deputy, was indicted in March 2014 on two counts of murder for killing his mother, Carol Lavett Gary, 43, and her son, Patrick Earl “PJ” Gary Jr. at their South Oaks home in the early morning hours of Nov. 8, 2013.

On Tuesday, he pleaded guilty before Circuit Court Judge John Kelly Luther to two counts of second-degree murder. He was originally charged with first-degree murder but the charge was reduced in the plea agreement.

He was sentenced to 40 years in prison with 16 years suspended on both charges, leaving 24 years to serve, followed by five years of probation after release. Both sentences were ordered to run consecutively, meaning he must finish one sentence before he begins serving the other, leaving a total of 48 years to serve.

Mister, 27, will not be eligible for “good behavior” time off of his sentence. According to the Mississippi Department of Corrections, he will serve every day of the 48 years. Should he live long enough to fulfill his sentence, he will be released and will be on parole for five years. He will be 75 years old when he completes his sentence.

Mister, who served as a school resource officer for the Water Valley School District, lived with his mother at the time of the shooting.

Gary was the principal of Davidson Elementary in Water Valley at the time she was killed. She had just started the job in August before her death. Her son PJ was a seventh-grader at Oxford Middle School.

No motive for the shootings was released, but some close to the victims said Regis’ mental health was questionable. He was let go from the Yalobusha Sheriff’s Department for the misuse of a gas card.

In a letter submitted in February to the court, Mister asked a Lafayette County Circuit Court judge to consider allowing him out of prison so he can help his elderly grandparents and take an active role in his church. No mention of the shooting was made. In his letter, Mister said if a judge let him go he would give up his law enforcement certification, donate his gun and ammo to a local SWAT team. He said he didn’t want a felony on his record because it would make it hard for him to get a job.

Earlier this year, the court ruled Mister was capable to stand trial and was able to assist attorneys in his own defense, based on the findings of a mental evaluation.