By: AP via Scripps News Group

Sean Grayson, a former Illinois sheriff's deputy whose fatal shooting of Sonya Massey inside her home became a flashpoint over police use of force, died Sunday while serving a 20-year prison sentence.

Grayson's attorney, Daniel Fultz, confirmed that his client died earlier Sunday but declined to provide any further details.

Grayson, 32, was convicted of second-degree murder in October in the fatal shooting of Massey, a 36-year-old Black woman who had reported a possible prowler outside her Springfield-area home. Body camera video of the July 2024 encounter showed Massey crouching in her kitchen and apologizing moments before Grayson shot her in the face.

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He was sentenced in January to the maximum 20 years in prison.

Grayson had been diagnosed with colon cancer before Massey's killing, and his attorneys said at his sentencing that the disease had spread to his liver and lungs. In May, only months into his sentence, he sought medical release under an Illinois law for prisoners with terminal illnesses or serious medical conditions. The Illinois Prisoner Review Board denied his request last month.

Massey called 911 early on July 6, 2024, to report someone prowling outside her home. Grayson and another Sangamon County sheriff's deputy responded.

Sean Grayson, a former Sangamon County Sheriff's deputy who is charged with first-degree murder in the shooting death of Sonya Massey.

Video showed Grayson directing Massey to remove a pot of hot water from the stove. As she held the pot, Massey told the deputies, "I rebuke you in the name of Jesus."

Grayson threatened to shoot her, drew his handgun and ordered her to drop the pot. Massey apologized and ducked behind a kitchen counter before Grayson fired three times.

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The other deputy, Dawson Farley, later testified that he did not consider Massey a threat and drew his own weapon only after Grayson did.

Grayson was fired after the shooting and charged with first-degree murder. Jurors convicted him of the lesser charge of second-degree murder after Grayson argued that he feared Massey would throw the hot water at him.

Massey's killing drew national attention and protests and raised questions about how Grayson had moved through several law enforcement agencies before being hired by the Sangamon County Sheriff's Office.

Donna Massey, center right, wipes tears from her face as she listens to Rev. Al Sharpton, right, speak during a press conference over the shooting death of her daughter, Sonya, who was killed by Illinois sheriff's deputy Sean Grayson, at New Mount Pilgrim Church in Chicago, July 30, 2024.

Illinois lawmakers later passed the Sonya Massey Act, requiring law enforcement agencies to more closely review an applicant's previous employment records before hiring an officer.

The Justice Department also opened a civil rights investigation after Massey's death and later reached an agreement with Sangamon County, its sheriff's office and other agencies requiring changes to policing and emergency response. Those changes included additional training for interactions with people with behavioral health disabilities and the development of a mobile crisis response program.