HILLSBOROUGH COUNTY, Fla. — The Hillsborough County sergeant who was fired on Friday and charged with assault with a deadly weapon has been investigated by the Sheriff's Office in the past.

Sgt. Janak Amin, a 21-year-year veteran with the Hillsborough County Sheriff’s Office, was involved in a deadly deputy involved shooting in July 2007 in Riverview.

Amin and another deputy responded to the home where a former Sarasota firefighter was uncooperative and waving a gun in his front yard.

Investigators found the shooting justified after Amin and the other deputy demanded William Best drop the gun numerous times before they fired.

The Sheriff's Office released the 145-page Internal Affairs report as part of a document dump after Amin's arrest on Friday.

Hillsborough County Sheriff Chad Chronister said in a press conference Amin responded to an area where an inmate had escaped.

The sheriff's office says that inmate was mistakenly taken to a mental facility, but he later walked out and was reported missing.

Several deputies on the scene reported that Amin held a gun to the man's head and threatened to shoot if he did not give him identification.

Other deputies on the scene de-escalated the situation and later reported it to command staff.

Amin was fired and arrested shortly after the incident.

"What I think bothered them the most was how egregious it was," Chronister said.  "What I think bothered them the most was how egregious it was. You had a person on the ground in a prone position and you have a sergeant with his firearm pointed toward the individuals head, inches away from his head ..."

If Amin is found guilty of assault with a deadly weapon, he could face a minimum mandatory sentence of 10 years in prison under Florida's 10-20-Life law.