Two outside investigators looking into the death of Tamir Rice have concluded that a Cleveland police officer, Tim Loehmann, acted reasonably in deciding last year to shoot when he confronted the 12-year-old boy carrying what turned out to be a replica gun.

Those opinions, reached separately by a Colorado prosecutor and a former F.B.I. supervisory special agent, were released Saturday night by the Cuyahoga County prosecutor, Timothy J. McGinty, whose office will ultimately present evidence in the case to a grand jury to decide on possible criminal charges.

“The question is not whether every officer would have reacted the same way,” Kimberly A. Crawford, the retired F.B.I. agent, wrote in her report, which noted that Officer Loehmann had no way of knowing Tamir’s gun was fake. “Rather, the relevant inquiry is whether a reasonable officer, confronting the exact same scenario under identical conditions could have concluded that deadly force was necessary.”