The capture of Saif al-Islam Gadhafi represents a test for Libya's new leaders as they face pressure to surrender him to a war-crimes court in the Netherlands.
The International Criminal Court in The Hague, acting on a request by the United Nations Security Council, issued an arrest warrant in May for Mr. Gadhafi, the eldest son of Colonel Moammar Gadhafi, the former Libyan dictator who once dismissed the rebels as "rats."
He is charged as an alleged "indirect co-perpetrator" of murder and crimes against humanity in connection with the brutal attacks on civilians after the revolution broke out in February. Abdullah al-Senoussi, his father's intelligence chief who was reported captured on Sunday, faces similar charges.
Under international law, Libya is supposed to surrender both men to the ICC for trial. A number of international rights groups, including Amnesty International and Human Rights Watch, are urging that they be transferred immediately.
But leaders of Libya's revolutionary National Transitional Council say they want the men tried in Libya. The ICC's chief prosecutor for the Libya cases is due in Tripoli this week to discuss the matter. Both defendants, meanwhile, remain in the hands of the militia fighters who seized them. A delicate tug-of-war is under way, with Libyan officials insisting they are in control and can run a fair trial despite lingering doubts outside the country.
Try him in Libya
Under the law that created it in 2002, the International Criminal Court is meant to be a court of last resort for prosecuting alleged war criminals whose own countries are unwilling or unable to try them. Libya's new leaders insist it is both willing and able.
An established judicial system and penal code exist in Libya, although they were manipulated by Col. Gadhafi. The revolution that ousted him began as a protest by outspoken human-rights lawyers demanding justice for the victims of a 1996 prison massacre. And Mustafa Abdul Jalil, the head of the National Transitional Council that now leads Libya, is a former Justice Minister widely respected for standing up to the Gadhafi clan.
"They're going to want to put something good together to help prove what they're capable of doing," said William Lawrence, North Africa project director for the International Crisis Group, a non-governmental organization that promotes peace.
Many of the leading figures on the National Transitional Council say they are eager for international advice and help, suggesting that a Libyan trial of Saif al-Islam Gadhafi and Mr. al-Senoussi might well be organized as a hybrid tribunal including international jurists.
There are models for such a compromise. A special mixed court, supported by the United Nations, is dealing with war crimes from Sierra Leone. Some of the war-crimes cases for the International Criminal Tribunal for the Former Yugoslavia have been transferred to a hybrid Bosnia-Herzegovina State Court that includes foreign judges and prosecutors.
If the defendants were prosecuted first by the ICC, Libya could later request that they be transferred home to face other charges such as corruption. But trying them from the outset in Libya would give prosecutors easier access to witnesses, particularly people who used to work in the Gadhafi government, and satisfy demands for a full accounting of the abuses of the Gadhafi regime.
Giving victims a chance to confront those who allegedly abused them can be cathartic and healthy for a society emerging from conflict, Mr. Lawrence said.
Try him at the International Criminal Court
Exhibit No. 1 in the argument for trying Saif al-Islam Gadhafi outside of Libya is the image of the bloodied corpse of his father, which was put on public display for days after his capture last month. Col. Gadhafi and another of his sons were alive when they were seized. They were dead within hours, in circumstances that remain unclear but point to summary execution.
The militia fighters that arrested Saif al-Islam Gadhafi have vowed to treat him humanely. But his safety before and during a trial in Libya cannot be guaranteed, according to international human-rights monitors who report continuing abuses in Libyan detention facilities and killings of those suspected of ties to the ousted regime.
The ultimate fate of Mr. Gadhafi and Mr. al-Senoussi is another concern. The two men would almost certainly face a death sentence if convicted of any of the raft of charges that Libyan prosecutors would bring. Capital punishment, anathema to most Western governments, is not among the penalties available to the International Criminal Court.
So a trial in The Hague, under international law on crimes against humanity, would be more reassuring to the countries that supported the arms embargo and the NATO strikes on the old regime.
It would be less likely to deteriorate into a public circus, as did the trial of Saddam Hussein in Iraq. It might also reduce the possibility that the proceedings get hijacked and overwhelmed by the rivalries and political divisions within Libya.
"In principle, we always want to see the trials take place in the country, if that's possible, and the ICC statute is based on that as well," said David Tolbert, president of the International Center for Transitional Justice in New York. "It's going to have a much greater impact, if it's done properly, than if it's done in The Hague or far away."
But the concrete question in this case is whether the still wobbling interim government is capable of organizing a fair trial and doing it quickly enough to satisfy Libyans.
The rebel council that has been running Libya has yet to appoint a government and most ministries are barely functioning. A cabinet is supposed to be announced this week. But it will have its hands full just establishing its credibility and authority over recalcitrant militias, like the one holding Mr. Gadhafi, that are lobbying for political positions and power.