TRIPOLI, Libya — An autopsy confirmed that Libyan dictator Moammar Gadhafi died from a gunshot to the head, the country’s chief pathologist said Sunday, just hours before Libya’s new leaders were to declare liberation and a formal end to an eight-month civil war to topple the longtime ruler’s regime.

The declaration starts the clock on a transition to democracy that is fraught with uncertainty and could take up to two years.

However, international concern about the circumstances of Gadhafi’s death and indecision over what to do with his remains overshadowed what was to be a joyful day. Gadhafi’s body has been on public display in a commercial freezer in a shopping center in the port city of Misrata, which suffered from a bloody siege by regime forces during the spring.

The 69-year-old was captured wounded, but alive Thursday in his hometown of Sirte as it became the last city to fall to revolutionary forces. Bloody images of Gadhafi being taunted and beaten by his captors have raised questions about whether he was killed in crossfire as suggested by government officials or deliberately executed.

An autopsy completed Sunday in Misrata showed that Gadhafi was killed by a shot to the head, said Libya’s chief pathologist, Dr. Othman al-Zintani. He would not disclose further details or elaborate on Gadhafi’s final moments, saying he would first deliver a full report to the attorney general.