CCTV images of a student who was stabbed to death in south-east London have been released by detectives.
The pictures show Samuel Guidera, 24, in a shop in Newlands Park about 20 minutes before he was found collapsed near Penge East train station.
It is thought Mr Guidera, who had been watching football with friends on Saturday, was the victim of a robbery.
Detectives hope the images of him carrying a pink T-mobile carrier bag will jog people's memories.
Mr Guidera, who had been studying history and politics at the the University of Greenwich, was found at Bailey Place in Sydenham at 2155 GMT on Saturday.
He was taken to hospital suffering from a stab wound but pronounced dead soon after.
Detectives said Mr Guidera had travelled on the 2117 GMT train from Bickley to Penge East.
He crossed over the railway footbridge and went into the local convenience store before walking towards the bus stop in Newlands Park where he was attacked.
He was found collapsed and a number of residents, car drivers, bus passengers and other pedestrians went to help thinking he had been hit by a vehicle, police said.
Tests showed he had been stabbed once in the heart.
Det Ch Insp Laurence Smith said: "We would urgently like to speak to anyone who may have seen Samuel on this Saturday evening, whether they saw him in the train carriage or saw him getting off.
"He was carrying a distinctive pink T-mobile carrier bag which some one may remember. Perhaps they saw him going into or leaving the shop?"