The Spanish driver whose train derailed, killing 78 people, has left hospital and is in custody on suspicion of negligent homicide.
Francisco José Garzon was pictured emerging bloodied from the wreckage of Wednesday's crash, when he allegedly told rescue workers: "I’ve f****d up, I want to die."
The train was travelling significantly faster than the 50mph limit on the bend at Galicia.
The 52-year-old had been in hospital since the crash under police guard, although his injuries were minor. He will appear before the investigating judge - who was too busy identifying victims on Thursday to question Garzon - on Sunday.
The country's interior minister, Jorge Fernandez Diaz, said: "There is rational evidence to lead us to think that the driver could have eventual responsibility."
Garzon has the right to remain silent, he added, "although he may change his mind on that."
The train's eight carriages, packed with 218 passengers, blazed far over the speed limit into a curve and violently tipped over. Diesel fuel powering the engine sent flames coursing through some cabins.
The president of Adif, the Spanish rail agency, said that the driver should have started slowing the train four kilometres (2.5 miles) before the bend. He said signs clearly marked this point when the driver must begin to slow.
Yesterday medical officials said 32 people who had been on the train were still in a critical condition, including three children.Reuse content