Garland's order comes on the heels of a Democrat push to prosecute more unruly passengers in light of the recent spike of attacks against flight attendants and staffers over COVID-19 masking guidelines.
"Passengers who assault, intimidate or threaten violence against flight crews and flight attendants do more than harm those employees; they prevent the performance of critical duties that help ensure safe air travel," Garland said in a press release on Wednesday.
"Similarly, when passengers commit violent acts against other passengers in the close confines of a commercial aircraft, the conduct endangers everyone aboard."
Garland issued the directive in a memorandum at the onset of the US holiday travel season.
The memorandum also highlighted an information-sharing protocol between the Federal Aviation Administration (FAA) and the Justice Department that helps ensure the latter is notified about criminal conduct occurring on commercial aircraft, the release said.
The protocol has already resulted in the referral of dozens of incidents by the FAA to the FBI for investigation, the release added.
Federal law prohibits assaults, intimidation and threats of violence that interfere with flight crews and flight attendants, as well as other criminal acts that occur during flight, according to the release.