Thirteen of Britain's most-wanted criminals, thought to be on the run in Spain, have been named by the National Crime Agency.
The list has been released as part of Operation Captura aimed at tracing criminals who are in hiding.
One of the 13, paedophile Michael McCartney, 78, from Letchworth, Hertfordshire, was detained in Alicante hours after the appeal.
The NCA said "Spain is not a safe haven".
This is the eighth appeal since Captura was launched in 2006, and so far 53 out of 63 named suspects have been caught.
Charity Crimestoppers said it was targeting wanted British citizens in Spain.
An NCA spokesman said McCartney, who was convicted of abusing three boys, was arrested at about 16:30 local time and is now due to appear before a Spanish court to face extradition proceedings.
He was found guilty in March 2013 but failed to attend court the following month to be sentenced.
Among the others in the group, dubbed the "unlucky 13" by Crimestoppers, is Robert Mortby, 26, from London, suspected of attempted murder over an attack on a man in Elephant and Castle.
He is suspected of being one of two men who attacked and shot a man in July last year.
Brian Thexton, 37, from Durham, is accused of being part of gang of robbers and is also awaiting trial for conspiracy to supply cocaine.
In one of the robberies the gang impersonated police officers to dupe the victims into opening the door, before brandishing a pick axe handle and a baseball bat.
All thirteen men are subject to a European Arrest Warrant (EAW) which would enable Spanish authorities to detain them and then extradite them to the UK.
Since 2009, a total of 277 British nationals have been surrendered to the UK by European police forces using EAWs.