Kensington police have identified a man they would like to locate in the investigation of an Armadale Train Line assault that ended in a man in a coma undergoing emergency surgery.
At around 6.30am on January 21, a 19-year-old man boarded a train bound for Armadale at Wellington Street train station.
Between Cannington and Beckenham stations the 19-year-old man and his friends became involved in an incident with another group on the train, during which he was punched to the head.
The assaulting group exited the train at Beckenham train station.
Shortly after, the assaulted man began to feel unsteady and was assisted to a seat on the Maddington train station platform in considerable pain before he was taken to Royal Perth Hospital and induced into a coma to undergo emergency surgery.
He remains in a critical but stable condition.
Police were seeking public assistance in locating Antionne Forrest-Yarran, 19, relating to the assault.
Mr Forrest-Yarran was described as dark skinned, about 187 centimetres tall, with a slim build, brown hair and with a tattoo on the left side of his neck.
They believe he frequents the Fremantle, Hamilton Hill and Maddington areas.
Anyone with information was asked to call Crime Stoppers on 1800 333 000 or make a report online at crimestopperswa.com.au.