At just after 9pm on 24 March, a man approached the 15-year-old victim at Gillingham railway station and put his arm around her.
They both then boarded a train to Chatham and when they arrived at the station he sexually assaulted her.
A short while later, the man again sexually assaulted her on-board a service travelling from Chatham to Rainham. They both alighted the train at Rainham and he led the victim to a nearby park where he exposed himself inappropriately.
If you recognise him, or have any information, please contact BTP by texting 61016 or calling 0800 40 50 40 quoting reference 731 of 24/03/22.
Alternatively, you can call Crimestoppers anonymously on 0800 555 111.