The US had him at Gitmo, but the Swedes set him free. Via TimesOfIsrael:
Bulgarian media on Thursday named the suicide bomber who blew up a bus full of Israeli tourists, killing five Israelis and a local bus driver, in the Black Sea resort of Burgas on Wednesday as 36-year-old Mehdi Ghezali.
Ghezali has a Wikipedia page, which describes him as a Swedish citizen, with Algerian and Finnish origins. He had been held at the US’s Guantanamo Bay detainment camp on Cuba from 2002 to 2004, having previously studied at a Muslim religious school and mosque in Britain, and traveled to Saudi Arabia, Afghanistan, and Pakistan, it says. He was taken into custody on suspicion of being an al-Qaeda agent, having been arrested along with a number of other al-Qaeda operatives.
Following a lobbying effort by Swedish prime minister Göran Persson, Guantanamo authorities recommended Ghezali be transferred to another country for continued detainment, and he was handed over to Swedish authorities in 2004. The Swedish government did not press charges.
A 2005 Swedish documentary about the Guantanamo Bay detention camp starred Ghezali, who detailed his experience in American custody.
He was also reportedly among 12 foreigners captured trying to cross into Afghanistan in 2009.