(CNN) - Investigators revealed Friday that the deadliest shooting rampage in Texas history, in which a disgraced airman massacred 26 people with legally purchased firearms, might have been avoided if the Air Force had alerted the FBI to the gunman's criminal history, as required under Department of Defense policy.
A damning new report by the Pentagon's inspector general reveals that the Air Force failed to share critical information with civilian law enforcement on multiple occasions and did not take steps that could have prevented 26-year-old Devin Kelley from buying the weapons he used to carry out the massacre at First Baptist Church in Sutherland Springs, Texas, and shoot himself in November 2017.
"If Kelley's fingerprints were submitted to the FBI, he would have been prohibited from purchasing a firearm from a licensed firearms dealer," the report says. "Because his fingerprints were not submitted to the FBI ... Kelley was able to purchase firearms, which he used to kill 26 people at the First Baptist Church of Sutherland Springs on November 5, 2017."
Federal law prohibits individuals convicted of misdemeanor crimes involving domestic violence from owning firearms. The military is required to report domestic violence convictions to civilian law enforcement.
While the Air Force has previously acknowledged it did not relay the killer's court-martial conviction for domestic assault to the FBI, IG investigators found that the service had at least four opportunities to share Kelley's fingerprints with the FBI but "never did so."
"We determined that this failure to submit Kelley's fingerprints was part of a systemic problem," the report said, adding that it had "drastic consequences."
As a member of the Air Force, Kelley served in logistics readiness at Holloman Air Force Base in New Mexico starting in 2010.
He was court-martialed in 2012 for two counts of Article 128 of the Uniform Code of Military Justice, assault on his spouse and assault on their child -- charges that resulted in a bad conduct discharge, confinement for 12 months and a reduction in rank, the Air Force previously disclosed.
"As described in detail in this report, in November 2012, while in the USAF, Kelley was the subject of two law enforcement investigations, one led by the 49th Security Forces at Holloman Air Force Base (HAFB), the other led by the Air Force Office of Special Investigations (AFOSI) Detachment 225," Friday's report says.
"As a result of the investigations, Kelley was convicted by General Court-Martial of an assault on both his wife and stepson, which is reportable to the FBI in accordance with DoD policy. This conviction should have prevented Kelley from purchasing a firearm from a licensed firearms dealer," it says.
Kelley was originally charged with assault and battery against his wife, aggravated assault against his stepson and four charges involving firearms -- including two charges of pointing a loaded firearm at his wife and two charges of pointing an unloaded firearm.
The firearms charges were dropped prior to trial as a result of a plea agreement. Kelley pleaded guilty to aggravated assault against the child and assault against his wife.
Despite his history of domestic abuse and questionable behavior involving firearms, Kelley was able to purchase the Ruger AR-556 rifle he allegedly used in the shooting from a store in San Antonio in April 2016, a law enforcement official said last year.
There was no disqualifying information in the background check conducted as required for the purchase, a law enforcement official told CNN at the time.
While Friday's report does not say that the Air Force is responsible for the shooting spree, it does note there was "no valid reason" why the service failed to relay crucial information to the FBI that should have prevented gun sales to Kelley.
"The failures had drastic consequences and should not have occurred," the report says. "In sum, we concluded that there was no valid reason for the USAF's failures to submit Kelley's fingerprints and final disposition report to the FBI CJIS Division."
The Air Force launched a review of all cases following the revelation that Kelley's information had not been properly sent to the appropriate civilian law enforcement agencies and found "several dozen" instances where records had not been properly relayed to the corresponding databases.
Air Force Secretary Heather Wilson said in November 2017 that the service will continue to review Kelley's case, along with others in various databases, for signs of mishandling but that she was not aware of past problems related to sharing criminal history data.
But government reports show the military has a history of inconsistently sharing information with the FBI -- a problem that was raised as early as 1997 in an inspector general report.
Several former military investigators previously told CNN that top officials have not only known for years about problems related to criminal-records handling within the Air Force Office of Special Investigations, but also that they stretch across all the service branches.
A 2015 report by the Pentagon's inspector general found that hundreds of fingerprints and final case reports held by the Navy, Air Force and Marine Corps had not been passed to the FBI's criminal history database. The branches had a compliance rate of about 70%, according to the report.
Copyright 2018 by CNN NewSource. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.