CHICAGO — Sean Grayson, the former Illinois sheriff’s deputy convicted in the fatal shooting of Sonya Massey, a case that became a flashpoint in the national debate over police use of force, died Sunday while serving a 20-year prison sentence, according to his attorney.

Grayson’s lawyer, Daniel Fultz, confirmed that his client died earlier Sunday but declined to provide additional details regarding the circumstances of his death. Grayson, 32, had been diagnosed with colon cancer before Massey’s killing, and his attorneys said at his January sentencing that the disease had since spread to his liver and lungs.

Grayson was convicted of second-degree murder in October in connection with the July 2024 shooting death of Massey, a 36-year-old Black woman who had called 911 to report a possible prowler outside her Springfield-area home. Body camera footage of the encounter showed Massey crouching in her kitchen and apologizing in the moments before Grayson shot her in the face. He was sentenced in January to the maximum 20 years in prison allowed for the conviction.

Only months into his sentence, Grayson sought medical release in May under an Illinois law that allows for the release of prisoners with terminal illnesses or serious medical conditions. The Illinois Prisoner Review Board denied that 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 to the call. Body camera video captured Grayson directing Massey to remove a pot of hot water from her stove. As she held the pot, Massey told the deputies, “I rebuke you in the name of Jesus.” Grayson then 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, striking her in the face.

The second deputy on scene, Dawson Farley, later testified that he did not consider Massey to be a threat during the encounter and said he drew his own weapon only after Grayson had already drawn his.

Grayson was fired from the Sangamon County Sheriff’s Office following the shooting and was initially charged with first-degree murder. Jurors ultimately convicted him of the lesser charge of second-degree murder after Grayson argued during trial that he had feared Massey intended to throw the hot water at him.

Massey’s killing drew significant national attention and sparked protests, while also raising broader questions about how Grayson had been able to move through multiple law enforcement agencies before ultimately being hired by the Sangamon County Sheriff’s Office. In response to those questions, Illinois lawmakers passed the Sonya Massey Act, a new state law requiring law enforcement agencies to more thoroughly review an applicant’s previous employment records before hiring an officer.

The U.S. Department of Justice separately opened a civil rights investigation following Massey’s death. That investigation later resulted in an agreement between the department, Sangamon County, its sheriff’s office and other local agencies, requiring a series of policy changes to local policing and emergency response practices. According to those terms, the changes included additional training for officers on interacting with individuals experiencing behavioral health crises, along with the development of a mobile crisis response program intended to provide alternative support for situations involving mental health concerns.

Beyond the criminal case and subsequent policy reforms, Massey’s family separately reached a $10 million civil settlement with Sangamon County over the fatal shooting, according to prior reporting on the case.

Grayson’s death closes out the criminal portion of a case that had continued to draw national scrutiny well beyond his conviction and sentencing, given both the circumstances captured on body camera footage and the broader questions his hiring history raised about screening practices across law enforcement agencies. His death comes just months after he began serving his 20-year sentence and roughly one month after state officials denied his request for compassionate medical release related to his advancing cancer diagnosis.

As of this report, authorities have not released additional details regarding the specific circumstances of Grayson’s death within the prison system, and his attorney has not indicated whether any further statement will be issued. Massey’s case remains closely associated with broader national conversations about police accountability, officer screening practices and law enforcement interactions with individuals experiencing mental health or behavioral crises, conversations that directly informed both the Sonya Massey Act and the subsequent Justice Department civil rights agreement reached with Sangamon County following her death.