Detectives in the UK have renewed their appeal to find one of the world’s most wanted men.
On the third anniversary of her son’s death, his mother Tracey said she “will not let Josh down” as she campaigns to get the suspect’s face known.
Mr Hanson, from London, was stabbed in the neck in a bar in 2015. The Metropolitan Police says Mr O’Brien was flown out of the UK on a privately-chartered plane from Biggin Hill Airport following Mr Hanson’s death.
Detectives describe the 30-year-old, who speaks with a London accent, as “very well-connected and supported”. They believe he is being helped by criminal associates, who are providing him with money, false identifies and the means to move across borders.
Since Mr O’Brien fled the UK, he has had an enormous tattoo of an owl on his back, to cover up a previous smaller design.
Police in the Czech Republic managed to photograph it when he was arrested for criminal damage there last year. He gave a false name and was released, with police only discovering his true identity later.
After the attack on Mr Hanson, Mr O’Brien possibly went to the Netherlands and United Arab Emirates, before returning to Europe. A £50,000 reward is being offered for information leading to his prosecution. In May, he was added to Interpol’s most-wanted list.
Earlier this week, Tracey wore a sandwich board, with details of her son’s murder, at train hubs in London to appeal for possible sightings.
She said “some people have still not heard about Josh” and added: “I thought about what might work and this grabs the attention of the commuter walking past. “More people are engaging with us now and we are getting more requests for wanted posters.”
Det Ch Insp Noel McHugh, who is leading the case for the Met Police, said: “For Josh’s family, the last three years, more than 1,000 days and nights without Josh – have been horrendous. “No words adequately describe the pain they are going through.”
Mr O’Brien is believed to have been travelling “extensively” with sightings reported in Gibraltar, Nice and Prague. He is known to like boxing and police hope any sports clubs around Europe, who recognise the tattoo, will get in contact.