A Baltimore man was sentenced to 18 months in federal prison Thursday for groping a woman who slept in the seat beside him on a flight home.

Deo Mugabe, 27, admitted to touching the woman’s breasts and putting his hands in her pants during their flight to BWI Marshall Airport from Houston last summer.

“She thought she was safe falling asleep on an airline flight, as many of us do, and she woke to find the defendant’s hands down her pants,” Assistant U.S. Attorney Ayn Ducao told the judge.

Federal prosecutors routinely charge such men with the felony crime of sexual assault aboard an aircraft. They allowed Mugabe, however, to plead guilty to three misdemeanor counts of assault. During his sentencing hearing, prosecutors and defense attorneys agreed on the lesser charge to protect his immigration status.

Mugabe was born in the Democratic Republic of Congo, and by age 2 his family fled to refugee camps in Rwanda. He has no criminal record. Christian Lassiter, his public defender, told the judge that deportation would have “dire consequences.”

Mugabe briefly addressed the judge. “I’m sorry for what I did.”

His case drew attention and came amid a series of assaults on airplanes. Last summer, a Detroit man was convicted of sexual abuse onboard an aircraft for groping a woman who slept in the seat beside him on an overnight flight from Las Vegas. She woke up to find her pants unbuttoned and unzipped. He was convicted at trial and sentenced to nine years in federal prison.

Also last summer, a man from Alaska was charged with sexual abuse on an airplane for grabbing the breast and thigh of a woman seated beside him on a flight to Seattle. He pleaded guilty and received three years of probation with eight months on house arrest.

Meanwhile, a California man awaits trial on federal charges that he assaulted a woman who slept next to him during a flight from London to Seattle. He ordered the woman a glass of wine before she fell asleep. She woke to find his hands down her pants, federal prosecutors say. They say he exposed himself, too.

Such encounters led federal authorities to warn travelers last summer about an apparent increase in sexual assault on airplanes. By November, the U.S. Department of Transportation announced the formation of a task force to review how airlines handle assault in the air.