(CNN) -- The Cuyahoga County Sheriff's Department on Saturday released an investigation report in the Cleveland police shooting of 12-year-old Tamir Rice. While offering no opinion whether two officers should be prosecuted, the report reveals new detail about the shooting.

A city police officer shot and killed Rice on November 22. A citizen had called the 911 center to report a \"guy with a pistol\" outside a city recreation center, but the responding officers weren't told the caller said the gun might be \"fake\" and the guy might be a juvenile. Rice actually had a pellet gun.

Will the officer and his partner be charged? On Thursday a judge said he thought there was probable cause, but his opinion is not binding. A grand jury will study this investigation report and decide whether to indict.

Here are some of the report's major takeaways:

It's unclear whether officer shouted warnings before shooting

The police department has said Officer Timothy Loehmann \"shouted verbal commands\" from inside his patrol car before firing at Rice, but the report says witness interviews don't back up that statement. Loehmann and his partner, Frank Garmback, didn't talk to the sheriff's office investigators. The patrol car didn't have a dashboard camera and security video cameras at the recreation center don't have audio. One woman who lives nearby said she heard two popping sounds, then shouting, then a third popping sound. Loehmann only fired two shots, however.

Police didn't immediately render first aid to Rice

An FBI agent happened to be in the area following up a bank robbery, heard about the incident and arrived about three minutes after the shooting. He found Rice lying on the ground. The two officers appeared upset and shell-shocked, he said, wanting to help Rice but not knowing what to do. The agent, a national registered paramedic who'd served in the military, tried to stop the bleeding and got assistance from an officer when he asked for it. Janell Rutherford, supervisor for patrols in that area, said patrol cars were not equipped with first-aid kits and officers had no first-aid training beyond basic CPR.

All the officers thought Rice was older than 12

The initial call to 911 described a male with a gun at the recreation center, who might have been a juvenile. Officers at the scene said they thought Rice was 16-20 and the FBI agent said he first thought Rice was \"eighteen-ish,\" based on his size. Rice was 5 feet 7 and weighed 195 pounds, according to the autopsy. The agent said he heard Rice's sister screaming that he was only 12 years old. The agent said, \"I remember thinking to myself, I'm like, 'There's no way.' And I looked at his face, I'm like, 'Yeah.' He's got a young-looking face. ...\"

The air pistol looked very real, police said

Rice traded a cell phone to a friend for the pistol. The friend told investigators he'd taken the air pistol apart and couldn't refasten the orange tip that distinguishes air pistols from real ones. The gun is listed as a \"replica firearm,\" a Colt 1911 target pistol that's 11.25 inches long. One officer said it looked \"a thousand percent real.\"

Rice talked to the FBI agent before dying

\"I asked him his name which he replied to me -- told me, and then he said that he was shot and he made a reference to his, uh, regarding like a gun or a question like, 'Where's my gun?' ... I can't remember exactly what it was. I just remembered that he made reference to a firearm.\"

Loehmann talked to the FBI agent

Though he didn't talk to Cuyahoga County investigators, Loehmann talked briefly to the FBI agent while he sat in a patrol car nursing an ankle injured during the shooting at the rec center. Loehmann said, \"He [Rice] had a gun and he reached for it,\" according to the agent.

Rice was shot at close range

Loehmann fired from a distance of 4.5 to 7 feet from Rice. The patrol car rolled onto the grass at the Cudell Recreation Center and Loehmann exited the vehicle and fired twice within two seconds.

Cleveland police were investigating the shooting, but amid calls for an independent investigation, the Cuyahoga County Sheriff's Department was brought in. Many of the interviews with witnesses were conducted in March, more than three months after Rice was killed.