A Louisiana man will spend the rest of his life behind bars after pleading guilty to fatally shooting his estranged girlfriend in her sleep.

Shawn Chiasson, 28, pleaded guilty to second-degree murder on Wednesday for shooting Lindsey Williams, 29, in the head while she slept in her bedroom on Aug. 14, 2021, according to a press release from the Office of Jefferson Parish District Attorney Paul D. Connick. Williams’ 11-year-old son was in a nearby bedroom during the shooting.

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Chiasson’s murder trial abruptly came to an end when he changed his plea from not guilty to guilty.

According to the release, jurors, who were seated last week, had heard the prosecutors’ opening statement, testimony from the victim’s mother, and were halfway through the direct examination of Chiasson’s ex-girlfriend when he changed his plea.

Prosecutors said that on the night before her murder, Williams joined friends at a restaurant in downtown Gretna, followed by a gathering on the Mississippi River levee. Chiasson then showed up at the same location, texting Williams a chilling message: “I’m looking dead at you.”

The following morning, just before 9 a.m., Williams’ son was in his bedroom when he heard a disturbance from across the hall in his mother’s room. The boy went to investigate the noise and opened the door to his mom’s room to see Chiasson with blood-soaked hands.

Chiasson then called 911 from the kid’s cellphone, identifying himself to the operator as “Jake,” and reporting a shooting, according to district attorney’s office.

Chiasson then fled the scene, notes the release, while the victim’s son waited on the front porch of the house for police to arrive.

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Following Chiasson’s arrest two days after the shooting, he told detectives that the pistol that killed Williams accidentally fired as he removed it from the waistband of his pants, according to prosecutors.

In addition to the second-degree murder charge, Chiasson pleaded guilty to being a convicted felon in possession of a firearm. He was prohibited to carry one due to a 2021 conviction of possessing heroin. On top of his life sentence for the murder, he was handed an additional 20 years for the firearm charge, as well as 40 more years for obstruction of justice for dumping the pistol used to kill Williams along a Westwego, Louisiana canal bank after the shooting. The judge ordered the sentences to be served consecutively, the release stated.  

The jury was unaware of the change in plea as they briefly left the courtroom Wednesday. The judge called them back to inform them that Chiasson had pleaded guilty, and the jurors then voluntarily remained in the courtroom to listen to Chiasson’s sentencing, as well as the victim impact statements.

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Family members told NBC affiliate WDSU that Williams was a loving mother and a physical therapist.

They said that while the couple had separated, Williams allowed Chiasson to stay in her home during his job hunt.

“Best mother, best daughter, granddaughter, friend, everything you can imagine,” Williams’ mother, Ann Williams, told WDSU. “She just lit up a room. She was the life of the party.”

Williams’ mother added that, with the abrupt ending to the murder trial, she is glad that Williams’ now 13-year-old son did not have to testify.

If you’re experiencing domestic violence or know someone who is, call 911 or the National Domestic Violence Hotline at 1-800-799-SAFE (7233) or visit thehotline.org.