The "police use-of-force" expert who wrote one of two reports that deemed the fatal police shooting of 12-year-old Tamir Rice in November was "reasonable" was also instrumental in clearing Colorado officers in the fatal shooting of a 17-year-old girl.

S. Lamar Sims, a senior deputy district attorney in Denver, Colorado, was hired by the Cuyahoga County Prosecutor’s Office to conduct an independent review a Cleveland, Ohio police officer's use-of-force against Rice ahead of a grand jury trial. The inquiry will attempt to determine whether Officer Timothy Loehmann, who is white, used reasonable force in shooting the 12-year-old Rice, who was black, because he was perceived as being “a serious threat.”

Sims' 52-page report was released on October 10. The report will be one of several items a grand jury will consider when weighing whether Loehmann and his partner, Frank Garmback, will be charged with a crime.

Experts defend cop who shot & killed 12yo Tamir Rice for carrying toy gun http://t.co/Bob79M8UWTpic.twitter.com/09DbnYG46T — RT America (@RT_America) October 11, 2015

"There can be no doubt that Rice's death was tragic and, indeed, when one considers his age, heartbreaking," Sims wrote in the report. "However, I conclude that Officer Loehmann's belief that Rice posed a threat of serious physical harm or death was objectively reasonable as was his response to that perceived threat."

"The officers did not create the violent situation” with Tamir Rice, per Denver’s deputy district attorney. Rubbish. http://t.co/ROHUGmtAIr — Jamil Smith (@JamilSmith) October 11, 2015

The Denver prosecutor asked to investigate the killing of Tamir Rice said this. Appalling. http://t.co/7uqRkrv84Xpic.twitter.com/RB9kNJPqa0 — Jamil Smith (@JamilSmith) October 11, 2015

On November 22, 2014, the Cleveland Police Department received reports concerning a male with a gun at a playground. A cruiser with Officers Loehmann and Garmback arrived on the scene shortly after. Police said Loehmann engaged when Rice reached into his waistband, and that officers did not realize that he was carrying a toy weapon. Loehmann fired two shots at Rice, which struck him in the abdomen, and the boy subsequently died from his wounds in hospital the following day.

READ MORE: Cleveland police dispatcher involved in shooting of 12-yr-old Tamir Rice resigns

Rice's "gun" was found to be an Airsoft replica. It lacked the orange safety feature visualization to show that it was, in fact, a fake.

As a member of the Denver District Attorney's Office, Sims was a contributing researcher in a report that cleared police of responsibility for the controversial January 26 killing of Jessica Hernandez, a 17-year-old who was sleeping in the driver's seat of a stolen car with four friends when two Denver police officers approached the vehicle.

The officers, on the scene after a tip about a suspicious vehicle in an alley, demanded the teens get out of the car. Hernandez started the car and accelerated. Both officers fired, only hitting Hernandez.

READ MORE: Denver cops’ shooting of 17yo girl in car ruled ‘justified’

"Hernandez chose to not comply with those orders," the Denver report said. "Perhaps she feared being caught driving a stolen car. Perhaps her judgment was impaired by marijuana and alcohol. We can draw these inferences from the facts. However, what is clear from the facts and needs no inference, is that her decisions created a very dangerous situation -- not just to herself and to the officers, but also to her friends who were in the car with her."

When Tamir Rice's killers + their accomplices sought justification for murdering a 12-yo Ohio boy, where did they turn? To Denver, Co. — elisabeth. (@elisabethepps) October 11, 2015

(1) Denver DAs Doug Jackson & S. Lamar Sims say #JessieHernandez deserved to die; (2) Sims says #TamirRice did too. pic.twitter.com/LPgPZ5fmRo — elisabeth. (@elisabethepps) October 11, 2015

Sims' role in both the Rice and Hernandez reports ‒ which mirror one another in justifications for police use of deadly force ‒ was first reported by the Northeast Ohio Media Group.

In March, Sims gave a speech at an event held by Cuyahoga County Prosecutor Timothy J. McGinty. Sims said at the time that it is difficult to prove an officer did not shoot a suspect based on belief that their life or someone else's life was in danger.

"The perceptions that most people have are not based on an understanding of the law, or the realities of force," Sims said at the appearance.

READ MORE: 11yo Illinois boy arrested for playing with toy gun

McGinty has been slammed by Rice's family and their attorney, as well as by groups like the ACLU of Ohio, for the reports, both of which were done by individuals with law enforcement backgrounds; the other report was prepared by retired FBI agent Kimberly Crawford.

"If you look at the credentials of [Crawford and Sims], they're not community activists," Christine Link, executive director of the ACLU of Ohio, told Northeast Ohio Media Group. "They're not people who experience police work from the receiving end. They're law enforcement officials."

"Not to oversimplify, but you've seen 'Law and Order,' the police and prosecutors are on the same side," she continued. "There's this idea that they come to the work with no bias. Really? We have to admit that we all come to our work with bias."

The Rice family attorney told RT that in soliciting these reports, McGinty attempted to "make opinion early to soften the blow" if and when the grand jury does not indict the officers.

“What he should be doing, as in any other grand jury, he should be looking to answer a simple question: ‘Is there probable cause that a crime has occurred?’ That’s it,” Rice family attorney Walter Madison said on Monday.

“The grand jury’s function is not to exonerate or exculpate any individual. When you go off and seek expert opinion – and all of this is occurring without anyone there and behind the door, in secrecy – it’s problematic. It really underscores why he [McGinty] shouldn’t be in charge of the investigation in the first place. All of these concerns, or the perception by the public, that this is not going to be a fair outcome, would be alleviated if there were just an independent prosecutor from the start. ”

Rice’s death came only two days after a grand jury in St. Louis County decided not to indict Darren Wilson, at the time an officer with the Ferguson Police Department in Missouri, over an August 2014 incident in which he fatally shot Michael Brown, an unarmed black teen.