Illinois deputy pleads not guilty to murder in fatal shooting of Springfield woman who called 911

SANGAMON COUNTY, Ill. -- A Sangamon County Sheriff's Deputy charged in the shooting death of a woman who called police for help has pled not guilty.

Deputy Sean Grayson has been charged with murder, authorities said Wednesday. He made his not guilty plea on Thursday.

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The Sangamon County State's Attorney said he fired on Sonya Massey as he responded to her home in Springfield, Illinois, earlier this month.

Two Sangamon County Sheriff's Office deputies were dispatched to the Springfield residence at about 12:50 a.m. to investigate a prowler, according to a statement from the sheriff's office obtained by ABC News.

"At approximately 1:21 a.m., the Deputies reported that shots had been fired, resulting in a female being struck by gunfire," according to the sheriff's initial statement. "The woman was transported to St. John's Hospital, where she was later pronounced deceased. No deputies were injured during the incident."

Massey, 36, was pronounced dead at 1:47 a.m. on Saturday after being transported to an area hospital, Jim Allmon, Sangamon County Coroner, told ABC News in a statement.

"An autopsy was performed, and preliminary findings show Ms. Massey died from a gunshot wound," Allmon's statement said. "The death remains under investigation by the Illinois State Police and the Sangamon County Coroner."

The Illinois State Police, who have taken over the investigation, told ABC News in a statement that they would not yet share body camera footage "to protect the integrity of the legal process and the right to a fair trial in the event charges are filed."

Governor JB Pritzker called the charges appropriate in a statement Wednesday night and said he is enraged by the shooting.

The sheriff's office told ABC News in a statement that it requested that the ISP conduct an independent investigation into the incident.

"ISP is collaborating closely with the Sangamon County State's Attorney's Office to conduct a timely, comprehensive, and transparent investigation," according to a statement by the state police.

Civil rights attorney Ben Crump, who Massey's family has retained as legal counsel, says Massey was shot and killed in her own home after calling 911 to report an intruder. ABC News has been unable to independently verify this information.

"It is extremely hard to imagine how a woman who calls the police out of fear of an intruder ends up shot in the head by the police at her own home," Crump said in a statement to ABC News. "We demand that all body camera footage from this incident be released immediately so that Sonya's family and the public can see what happened in those 30 deadly minutes."

Supporters of the family held a protest in Springfield, Illinois, on Friday demanding justice and accountability in Massey's death.

John Milhiser, the Sangamon County state attorney, confirmed with ABC News in a statement that his office is working with state police on the investigation but could not release any further information at this time.

Authorities did not release the name of the deputies on the scene when Massey was shot.

"When appropriate, additional information, including the video, will be shared with Sonya Massey's family before releasing further," according to a statement from state police.

ABC7 Chicago contributed to this report.