Lawyers for a 15-year-old Kansas boy accused of fatally shooting his drunk mother are trying to dismiss the case, saying he “acted bravely and legally” by defending himself and his younger brother.

The teen, who wasn’t named because he’s a minor, was recently charged with voluntary manslaughter in the June 20, 2018, death of his mom, 41-year-old Lisa Trimmell, at a mansion near Andover, The Wichita Eagle reported.

The siblings, who were then 14 and 12, were at the mansion that night spending court-ordered time with their mom, after their orthodontist dad, Dr. Justin Trimmell, had moved out and taken them with him. The parents were in the midst of a divorce.

In their motion to dismiss, defense attorneys say Lisa Trimmell was wasted and physically attacked the 12-year-old boy.

The older brother grabbed his mom’s gun and “fearing for the life of his younger brother, as well as his own,” shot her and then called 911, according to the court documents.

A bullet hit Trimmell’s neck and severed her spine, according to the autopsy report. There were also 16 blunt-force injuries to her body.

The autopsy also found that Trimmell had “acute and chronic alcoholism” and scarring of the liver. Her blood-alcohol level at the time of the autopsy was 0.185 — more than double the legal limit for driving in Kansas.

“For many years, Lisa Trimmell was a devoted, loving mother who raised two intelligent, polite and well-behaved young boys to lead good lives,” Dan Monnat, a defense attorney for the older brother, told The Eagle.

“But, the autopsy confirms her death is another instance of the rampant disease of adult alcohol abuse leading to tragic results. Lisa long suffered the effects of chronic alcoholism, including physically abusing her two young boys.”

Before the mom’s killing, a counselor determined that her sons suffered from post-traumatic stress disorder as a result of her previous physical and psychological abuse, the defense attorneys wrote. She was apparently told that drinking would trigger their PTSD.

“This tragic event should not now be made more tragic by second-guessing the difficult decisions made that night through the prosecution of a child,” Monnat said. “Under clear Kansas law, children have as much right to defend themselves and their siblings against repeated acts of violent abuse as anybody else.”

The boy is scheduled to appear in juvenile court Friday, the Sedgwick County District Attorney’s Office said.