The FBI agent who treated Tamir Rice moments after he was shot by a Cleveland police officer last year told investigators that the officer who killed him looked shaken after the fatal rounds were fired, according to details of a sheriff’s department investigation of the shooting.

The agent, whose name was withheld, was the first person to attempt to give medical aid to Tamir after Officer Timothy Loehmann shot the 12-year-old to death on Nov. 22, according to interviews and police documents.

“The officer seemed pretty concerned,” the unidentified agent said, according to a transcript of an interview with Cuyahoga County Sheriff’s Department investigators. “Obviously very concerned and uh, I don’t want to use the word like – almost like shellshock; like they didn’t know what to do.”

The report makes no recommendation on whether criminal charges should be filed in the case.

Loehmann killed Tamir after responding to reports of a person waving a gun. The 911 caller told police that the person was probably a child and that the gun was probably fake, but that information was not relayed to the rookie officer.

Shortly after the shooting, Loehmann told another officer that he had “no choice” but to shoot the boy as he held a toy weapon, according to the report.

“He reached for the gun and there was nothing I could do,” the officer said Loehmann told him at the scene.

Loehmann, who remained seated in a police vehicle with an injured ankle after the shooting, made similar remarks to the unidentified FBI agent, according to the report.

Cuyahoga County Prosecutor Timothy McGinty made the case file, which contains hundreds of pages of interview transcripts, police emails, medical examiner’s findings and ballistics reports, public on Saturday. Many of the investigation documents were redacted to “exclude personal information, confidential medical records and reports not germane to the events of Nov. 22,” McGinty said.

“Transparency (i.e., the actual facts) is essential for an intelligent discussion of the important issues raised by this case,” Cuyahoga County prosecutor Timothy McGinty said in a statement released Saturday with a report on the Sheriff’s Department investigation of Tamir’s death. “If we wait years for all litigation to be completed before the citizens are allowed to know what actually happened, we will have squandered our best opportunity to institute needed changes in use-of-force policy, police training and leadership.”

McGinty’s office is conducting a review of the shooting and plans to present the case to a grand jury later this year.

The FBI agent and others described a chaotic scene in the park where Tamir was shot, according to the report. Tamir’s brother allegedly charged toward officers and threatened them, according to the FBI agent. His sister was handcuffed and put in a police car.

Tamir did not receive medical treatment until nearly four minutes after he was shot, according to the Sheriff’s Department investigation. Loehmann and his partner, Frank Garmback, radioed for help at the scene, and told medical personnel to rush to the area, according to the report.

Cleveland officers are given little medical training, a police supervisor told investigators, and none of the city’s police cars have first aid kits.

Loehmann and his partner were able to provide the FBI agent with only rubber gloves when he asked for medical supplies to treat Tamir, according to the report. While the FBI agent was the first to treat Tamir, Garmback did help clear the boy’s airways minutes later, the report said.

This week, a Cleveland municipal judge found probable cause to charge Loehmann with murder and several other offenses. His finding came days after a group of citizens and activists used a little-known Ohio law to argue for charges against the officers.

The judge also found probable cause to charge Garmback, who was Loehmann’s partner that night, with negligent homicide.

While the ruling has no legal bearing on the case, experts have said the fact that a sitting judge found probable cause to charge the officers could influence grand jurors, who unlike trial jurors are allowed to review media reports of a pending criminal matter.

In Loehmann’s defense, police have said that he warned the boy to drop the weapon, and union leaders said Loehmann had no choice but to fire since he believed Tamir, who was black, had a weapon.

Many of the officers who arrived at the scene that night and saw the toy gun lying on the ground told investigators they also believed the weapon looked real. One described it as an “authentic firearm.”

In separate interviews with investigators, the boy who lent Tamir the toy gun also said he had disassembled it earlier in the week and was unable to reattach the orange tip to the barrel of the toy gun, which made it more closely resemble a real firearm.

Loehmann and Garmback did not cooperate with the sheriff’s department during its investigation, according to Steve Loomis, president of the Cleveland Police Patrolmen’s Association. They did, however, make statements to Cleveland Police internal affairs and homicide investigators on the day of the shooting, Loomis said previously.

Tension between prosecutors, residents and the police union has run high in recent months since another city police officer was acquitted on manslaughter charges for his role in a 2012 police chase that left two people dead.

In that case, prosecutors argued that the union was trying to insulate Officer Michael Brelo from criminal liability. Seven officers invoked their Fifth Amendment rights at trial, including two who weren’t facing criminal charges.

The sheriff’s report on the Tamir Rice shooting details similar issues: Investigators asked to speak with three dispatchers involved in the case. All of them declined to be interviewed after speaking with a police union attorney.