Sean Grayson, the former Sangamon County Sheriff\u0027s deputy convicted of murdering Sonya Massey in her home in 2024, died on Sunday.Attorney Daniel L. Fultz, who served as Grayson\u0027s attorney, confirmed the news on Sunday.Grayson had been battling Stage 4 colon cancer, for which he was undergoing treatment. It is unclear if that was the cause of death.Grayson, 32, was found guilty last October of\u00a0second-degree murder for the shooting\u00a0of Sonya Massey and was serving a 20-year sentence in the Illinois Department of Corrections, which was to be followed by two years of mandatory supervised release.Last month, the Illinois Prisoner Review Board rejected Grayson\u0027s medical release request and ordered him to remain in prison, despite the application citing advanced colon cancer. CBS News Chicago has reached out to the Department of Corrections, but has yet to hear back.What happened in the Sonya Massey shooting?In July 2024, 36-year-old Massey called police for help for a possible prowler outside her home. Grayson, along with another officer, responded to her home and spoke with her.\u00a0While inside the home,\u00a0Grayson\u00a0said Massey began acting erratically and saying that she rebuked him "in the name of Jesus" while walking towards a pot of water on her stove.\u00a0Bodycam video from Grayson\u0027s partner captured the moment he shot Massey, who\u00a0died of a gunshot wound.\u00a0Grayson\u0027s body camera was not activated for most of the call, only turning on shortly after he pulled his weapon.