In this image, a Spirit Airlines airplane sits at a gate at the O'Hare Airport in Chicago, Oct. 2, 2014. REUTERS/Jim Young

A federal jury Thursday convicted a man of sexually assaulting a sleeping woman on a Spirit Airlines flight from Las Vegas to Detroit in January.

According to U.S. Attorney's Office for the Eastern District of Michigan, 35-year-old Prabhu Ramamoorthy was convicted of undressing and penetrating the victim. The sentencing date was set for Dec. 12, 2018, and the convict could face up to life imprisonment.

Ramamoorthy was in the United States on a work visa and would be deported to his home country, which was not specified in the criminal complaint, after the sentencing.

According to the criminal complaint filed against him, the 22-year-old woman fell asleep leaning against the wall. When she woke up, she noticed the man in the middle seat next to her had his hands down her unbuttoned pants. She also noticed her shirt was unbuttoned and the man was fondling her, CNN reported.

She pushed past the man and his wife, who was seated beside him and immediately rushed to the back of the plane to inform the attendants. Ramamoorthy was taken into custody as soon as the flight landed.

The complaint stated he initially told the cops he had taken a pill and was in "deep sleep.” The woman fell asleep on his knees; however, he was "not sure where [he] kept the hand on her."

"Through my knowledge I didn't [sic] anything to her," he said.

However, he and his wife later said the pill was plain Tylenol and gave conflicting views of what happened, the prosecutors said. His wife, who has not been named in the complaint, said she had asked to switch seats as the woman had fallen asleep. However, the attendants told the investigators no one except the victim has asked to switch seats.

According to the complaint, Ramamoorthy later told an FBI agent that he "might have" unhooked the woman's bra. He also said he unzipped the pants and tried to put his fingers inside the woman but was unsuccessful, Straits Times reported.

A motion filed by Ramamoorthy’s attorney James Amberg to suppress his statements mentioned his client believed “anything he told police was inadmissible in court” as his understanding of the legal process was based on his home country's law.

U.S. Attorney Matthew Schneider said the prosecution presented evidence to prove he penetrated the woman with his fingers.

Praising the woman for her courage to speak up, Schneider said, "Everyone has the right to be secure and safe when they travel on aeroplanes. We will not tolerate the behavior of anyone who takes advantage of victims who are in a vulnerable position, and we are glad the jury agreed. We appreciate the victim in this case for her courage to speak out.”

It is still unclear if Ramamoorthy would appeal the conviction.

According to the FBI, which investigates crimes on aircraft, 63 sexual assault cases on flights were reported in 2017, up from 38 in 2014.