Aidan Fraley (right), 16-year-old son of slain unarmed Tulsa suspect Eric Harris (left); (top left) Oklahoma County Sheriff Stanley Glanz; (bottom left) 73-year-old Robert Bates. (AP Photos//Sue Ogrocki and File)

TULSA, Okla. (AP) — A grand jury will begin investigating allegations of wrongdoing against the Tulsa County sheriff’s office, which came under scrutiny after a reserve deputy shot and killed an unarmed and restrained suspect because he says he mistook his firearm for a stun gun.

Among the accusations that the grand jury is expected to consider after convening Monday is whether Sheriff Stanley Glanz gave special treatment to the reserve deputy, Robert Bates, who was a close friend of Glanz’s and had served as Glanz’ campaign manager in 2012.

Bates, a wealthy 73-year-old insurance executive who has since left the force, is charged with second-degree manslaughter in the April 2 killing of Eric Harris, a Black man, who had run from deputies after allegedly being caught in an illegal gun-sale sting.

Harris’ death quickly led to scrutiny of the management of the sheriff’s office, and particularly the relationship between Glanz and Bates, who also has donated thousands of dollars in cash and equipment to the sheriff’s office.

A civil rights group, We The People Oklahoma, gathered the thousands of signatures required to empanel a grand jury after a 2009 memo was leaked that called into question whether Bates was qualified to do his job.

The grand jurors will be asked to consider whether they believe Glanz neglected his duties or showed special treatment to Bates or other reservists who gave gifts to his office. They will hear testimony from witnesses whose appearances are coordinated by a legal adviser detailed to the case. Both the adviser and jurors ask questions of witnesses and the panel decides when it meets and for how long.

Marq Lewis, of We The People, speaks with the media following a county commissioner’s meeting, concerning Sheriff Stanley Glanz, in Tulsa, Okla., Monday, July 13, 2015. Officials reevaluated a contract they previously approved allowing embattled Sheriff Glanz to hire his own private defense team. Glanz’s office is under scrutiny following the shooting of Eric Harris by a volunteer sheriff’s deputy. (AP Photo/Sue Ogrocki)

It would require 9 of the 12 grand jurors — three alternates will also be chosen — to recommend an indictment or make an accusation for removal from office. The grand jury’s findings are read in open court.

The grand jury process allows residents a direct way to pursue grievances against their government, said John David Luton, a prosecutor with the Tulsa County District Attorney’s Office. His office recused itself from the case.

“It’s a right of the people that doesn’t require the assistance or the aid of a public official or someone related to the government to make a decision to take certain action,” Luton said. “This is action the people can take themselves.”

Glanz has said he is eager to tell his side of the story to a jury. However, his attorneys tried for weeks to prevent the grand jury investigation. The Oklahoma Supreme Court ruled Thursday that the investigation could proceed.

Terry Simonson, a spokesman for Glanz, didn’t respond to phone messages or emails seeking comment.

Marq Lewis, who helped organize the petition drive, said that regardless of what the grand jury decides, the process has shown citizens that the legal system can work.

“If nothing comes out, we don’t have our heads to hang. We’ll just accept what the findings are,” Lewis said.