>>> libya's interim leader declared this a new day, celebrating liberation after eight months of civil war and decades of oppression under moammar gadhafi. at the same time, charting the course to democracy, based in islamic law. but as the country's new founding fathers look forward, the u.s. among other countries is calling for some accountability to the past and the question of how gadhafi died. nbc's adrian among reports from misrata.

>> reporter:  a sea of red, black and green flooded benghazi's main square, the site where libya's uprising began eight months ago. hundreds of thousands celebrating liberation from 42 years of rule under moammar gadhafi. the leader of a transitional government thanked rebel forces for winning the war and stressed the need for tolerance and reconciliation among the different tribes. casting a shadow on the celebrations, however, questions still over gadhafi's death. as his corpse lay in misyacht for a third day, an autopsy confirmed he died from a bullet to the head no other details have been released. amateur video continues to emerge, showing his last chaotic moments alive. in another piece of new footage, a rebel soldier grass pz tps of gun of gadhafi's alleged killer saying, he's the guy that killed him. the u.s. and other nations are urging thorough investigations.

>> i think it is important that this new government, this effort to have a democratic libya start with the rule of law, start with accountability.

>> reporter:  fighters from the unit that found gadhafi in a drain pipe in his home on thursday said they don't care about how or when he died. the important thing, they say, is that he was caught. towards the end, the eccentric former leader was said to be growing impatient with life on the run. fighters who seized him said he refused to believe his time was up. in misrata, which put up some of the fiercest fighting against gadhafi's troops earlier this year, thousands of people again crowded into the recently renamed freedom square. some of them said they wanted to look forward, not backwards.

>> now you have to look about the future.

>> reporter:  today's declaration of liberation sets in motion a process that will ultimately end in the nation's first free election. already there is a sign of what a new and free libya will look like, transitional leaders have said that islamic sharia law will form the basis for all legislation. adri adrian mong, nbc news, libya.