ZINTAN, Libya – Moammar Gadhafi’s former heir apparent Seif al-Islam was captured by revolutionary fighters in the southern desert Saturday just over a month after his father was killed, setting off joyous celebrations across Libya and closing the door on the possibility that the fugitive son could stoke further insurrection.

Seif al-Islam — who has undergone a transformation from a voice of reform in an eccentric and reviled regime to one of Interpol’s most-wanted — now faces the prospect of trial before an international or Libyan court to answer for the alleged crimes of his late father’s four-decade rule over the oil-rich North African nation.

Thunderous celebratory gunfire shook the Libyan capital of Tripoli and other cities after Libyan officials said Seif al-Islam, who has been charged by the International Criminal Court for crimes against humanity, had been detained about 30 miles west of the town of Obari in an area that borders Niger, Mali and Algeria.

A photograph was widely circulated showing the 39-year-old son in custody, sitting by a bed and holding up three bandaged fingers as a guard looks on, although Osama Juwaid, a spokesman for the fighters from Zintan who made the arrest, said it was an old injury caused by a NATO airstrike and the detainee was otherwise in good health.

“I am hopeful that the capture of Gadhafi’s son is the beginning of a chapter of transparency and democracy and freedom,” Libya’s interim Prime Minister Abdurrahim el-Keib said at a news conference.

ICC prosecutor Luis Moreno Ocampo said he will travel to Libya this week for talks with the country’s transitional government on where the trial will take place.