POLICE in West Yorkshire want to trace this man connection with a campaign of malicious letters sent to schools and colleges across the UK.
The force said it had been investigating a large number of letters of concern, predominantly to educational establishments.
They want to speak to a man who is believed to be from the Merseyside area.
He was caught on CCTV as he travelled on a train from Liverpool to Ormskirk on Sunday, March 2.
A spokesman said he is believed to have got off the train at Ormskirk at about 1.40pm that day.
Anyone who believes they might know the man, or has any information that could help police, is asked to call 101, extension 28212, or Crimestoppers on 0800 555111, quoting the reference 13130024152.