Passenger Accused of Assaulting Sleeping Woman Midflight Then Slipping Her a Chilling Note

A disturbing incident aboard an international flight has led to federal charges after a passenger was accused of assaulting a woman while she slept — and then trying to contact her afterward with a note.

Authorities say 48-year-old Guillaume Sebastien Roger Mattler, a French national, was arrested after the flight landed in Miami following a trip from Zurich on April 28.

According to a federal criminal complaint, the alleged victim, a 29-year-old woman, had briefly exchanged polite conversation with Mattler before turning away and falling asleep in her seat.

What happened next was witnessed by multiple people onboard — including a flight attendant.

One passenger told investigators they saw Mattler touch the woman’s lower back, seemingly trying to make it look accidental. When she didn’t wake up, he allegedly did it again, this time for longer.

Another witness reported seeing him move his hand in a way that suggested he was trying to reach under her clothing.

A flight attendant who was alerted to the situation then approached and allegedly saw Mattler with his hand on the woman’s private area over her clothing.

At that point, crew members stepped in and moved him out of the first-class cabin to another section of the plane.

But the situation didn’t end there.

According to investigators, when Mattler was later allowed to return briefly to collect his belongings, he attempted to pass the woman a note that read, “You look beautiful when you are sleeping.”

The woman was eventually woken up by the crew and informed about what had happened. Authorities say she was shocked, shaking, and began crying, and confirmed she did not know the man.

After the plane landed, Mattler was taken into custody. Officials say he initially denied the accusations but later admitted to touching the woman after being confronted with witness statements and video evidence.

He allegedly told investigators he “did not think it was such a big deal” and claimed he had intended to ask for her phone number.

Mattler is now facing a federal charge of abusive sexual contact and is being held in a Miami detention facility as the case moves forward.

The incident has raised renewed concerns about passenger safety on long-haul flights — especially when victims are asleep and unaware of what’s happening around them.