The Pima County Attorney's Office has decided not to file any criminal charges against the deputy who tackled a 15-year-old boy with no arms or legs, then shoved another teenager's face into a wall.

In November, footage of Pima County Sheriff's Deputy Manuel Van Santen tackling a quadruple amputee at a group home in Tucson went viral and brought national scrutiny to the sheriff's department. Two days after the video was first published, on November 15, Pima County Sheriff Mark Napier authorized a criminal investigation into Van Santen's actions and placed him on administrative leave.

In a letter sent to Sheriff Napier on Tuesday, chief trial counsel Nicol Green said that the Pima County Attorney's Office declined to file any criminal charges against Van Santen in the incident because the "question" of whether the amount of force Van Santen used to restrain the teen was necessary "cannot be answered definitively."

"In order to pursue criminal charges, the state must have not just probable cause, but a reasonable likelihood of proving to a jury beyond a reasonable doubt that the physical force used was not immediately necessary to prevent [the teenager] from leaving the kitchen and again threatening the employee," Green wrote in the letter shared with Pima County Attorney Barbara LaWall. "That high burden cannot be met in this case."

Green also said that they would not charge Van Santen for shoving another teenager's face into a wall because, "while the video evidence does not corroborate resistance," the video, she claims, also does not definitively show that the teenager was not resisting. "The mere possibility that the level of force used was excessive is not a sufficient basis upon which to file criminal charges against the deputy," Green wrote.

The letter was first obtained and reported on by KOLD-TV, a CBS affiliate in Tucson which was also the first to publish the explosive video.

"Barbara LaWall endorsed Sheriff Napier for re-election," said Pima County public defender Joel Feinman. "The sheriff's office conducted the criminal investigation. The county attorney's office — full of prosecutors who have developed close ties with people from the sheriff's office whom they work with daily — reviews the criminal investigation and decides whether to file charges. And we're supposed to believe that can be objective? It's a farce."

The incident for which Van Santen will not face charges began on September 26, when a group home employee called police to complain that Immanuel, a teenager who has no arms or legs, had knocked over a trash can and was yelling.

He was upset, the employee said, because he had just learned he had been suspended and could not go back to school until Monday. The employee claims she felt threatened because the limbless teenager said he would knock her over as well.

Van Santen responded to the call around 10 a.m that day. When he arrived, Immanuel, whose last name is being withheld because he is a minor, tried to move away from him. Van Santen responded by violently pushing the limbless teen's face into the ground and pinning the boy there for several minutes.

Immanuel, who was shirtless and clearly upset, frantically screamed at the deputy not to hold him down. He tried to get away, but the deputy strengthened his hold on the teenager, pushing his body on top of Immanuel's and pressing him into the ground.

Eventually, Immanuel stopped trying to get away from Van Santen. The deputy then got off the boy, stood back up, and leaned down to yell and curse in Immanuel's face.

“I will raise my voice to you whenever the fuck I want, you understand?” Van Santen shouted.

Another boy at the group home captured the scene with his cellphone. When that boy said something, Van Santen told him to "shut the hell up" and that he would be arrested, too. A video shot by yet another group home resident shows that the boy was complying with the deputy and had his arms behind his back when Van Santen suddenly slammed the 16-year-old's face into a wall.

Immanuel was arrested for disorderly conduct, a misdemeanor, but the Pima County Attorney's Office said charges were dropped after officials reviewed the disturbing video.

Asked about his actions after the criminal investigation began, Van Santen told the Associated Press, "I can look my wife and my children in the face tonight and know that I did my job to the best of my ability. I look forward to clearing my name and returning to duty."

The Pima County Attorney's Office shared a press release with Phoenix New Times in response to a request for comment, essentially stating that officials had reviewed Van Santen's conduct as required by law, determined they could not convict him, and wouldn't comment any further.

The Pima County Sheriff's Department did not immediately respond when asked to comment on Van Santen and his future with the department.

"The conduct we observed on the video at face value is shocking, disturbing, and personally saddening to watch," said Pima County Sheriff Mark Napier in a press release issued after the video went viral in November.

Van Santen has been on administrative leave since November. While the deputy won't face any criminal charges for his conduct, an internal investigation remains ongoing and could potentially result in disciplinary action.

The lack of charges against Van Santen are "just further evidence that we really do have two justice systems," Feinman told New Times. "One justice system for police officers, correctional officers, and sheriff's deputies accused of crimes. And another justice system for everybody else."

"The two really look nothing alike: they have completely different standards of proof, different evidentiary rules, and different outcomes," Feinman said. "And it's just really sad that in our society we can indict millions of people on almost no evidence of drug possession, drug use, nonviolent victimless crimes ... and yet we have videos of police shooting people, videos an officer tackling a teenager with no arms and legs, and no matter how much evidence we have, it results in no justice and it results in no prosecutions."