Abdulmanon Aliev, 50, subjected the girl to a “prolonged” sexual assault as she travelled by train to London in June of last year.
An investigating officer said it was the worst sexual assault they had ever investigated.
Aliev was found guilty of two counts of assault by penetration, three counts of sexual assault and attempted rape at Inner London Crown Court today (April 9)
On the afternoon of June 16 2025, the teenager was travelling on a train from Southend to the capital.
Aliev, a Tajikistan national living on Rye Lane in Peckham, sat opposite the teenager and tried to use a translator app on his mobile phone to speak to her.
After she moved away from him, he followed her and sat beside her in an aisle, blocking her against the window.
The defendant then “forced himself” on the teenager and subjected her to a “prolonged sexual assault” until the service arrived at London, the BTP said.
She was able to get away from him at the station and boarded another train heading out of the city.
The teenager told fellow commuters what she had endured and the police were informed soon after.
The force trawled through hours of CCTV footage to track his movements before and after the attack and on June 27, more than a week after the incident, plain clothes officers spotted Aliev in Peckham and he was arrested.
Aliev will be sentenced at Inner London Crown Court on June 17.
BTP Detective Constable Elizabeth Cahill said: “Aliev singled out a vulnerable child and subjected her to one of the most abhorrent sexual assaults I’ve ever investigated.
“While the focus of attention will rightly be on him as the despicable sexual predator that he is, I want to pay tribute to the brave victim who reported him to police.
“This verdict would not have been possible without her account of what happened and her willingness to support our investigation.
“We take every sexual offence report extremely seriously, and we’ll stop at nothing to put offenders like Aliev before the courts.”