A woman in Oklahoma is heading to prison for shooting and killing her sister-in-law at a QuikTrip after the victim took her “marijuana grinder earlier in the day and refused to give it back,” according to federal prosecutors.

Alexis Flanner, 26, was convicted of second-degree murder after pleading guilty almost a year ago to purposely killing Estrella Mendoza, 37, who was married to Flanner’s brother, Aljuan Mendoza. She was sentenced to 20 years behind bars — 10 for a charge of second-degree murder and 10 for a charge of discharging a firearm during and in relation to a crime of violence, served consecutively — on Friday, according to a statement from the U.S. Attorney’s Office for the Northern District of Oklahoma.

“I admit that I shot Ms. Mendoza with malice aforethought in that I believed at the time that Ms. Mendoza would not return a marijuana grinder that belonged to me and I became angry with her,” Flanner said in her plea agreement on Feb. 28, 2024, court filings show. “I admit that Ms. Mendoza died as a direct and proximate cause of the gunshot would that I inflicted upon her.”

According to the criminal complaint, the victim’s husband was asleep in the car that he, his wife, and his sister had taken to the QuikTrip on the night of July 7, 2022. Mendoza’s husband told police that the three of them “had been drinking together” at a residence in Broken Arrow before the fatal shooting occurred.

“Aljuan advised he was asleep in the back of the vehicle when Alexis and E.M. (Mendoza) entered the store,” the complaint says. “Aljuan was awakened by a gunshot and saw E.M. (Mendoza) on the ground. Aljuan jumped up to render aid and stated E.M. (Mendoza) said to him, ‘your sister shot me,’ before going unconscious.”

Surveillance footage shows Mendoza “crawling away from Flanner” before she collapsed and died, according to the complaint. “Flanner was seen fleeing the scene,” it says.