A United Nations commission said the assassination of Pakistan's former prime minister Benazir Bhutto could have been prevented and blamed the government for failing to provide proper security.
It also accused intelligence agencies and other officials of severely hampering the investigation into those behind her murder.
Ms Bhutto was killed in a December 27, 2007, gun and suicide-bomb attack as she was leaving a rally in the garrison town of Rawalpindi, where she was campaigning to return her Pakistan People's Party to power in parliamentary elections.
There had previously been an attempt on her life when she returned to Pakistan 10 weeks earlier on October 18, 2007 after more than eight years in self-imposed exile.
The panel said her death could have been prevented if the government under then-President Pervez Musharraf, the Punjab state government, and the Rawalpindi District Police had taken adequate measures "to respond to the extraordinary, fresh and urgent security risks that they knew she faced".
The commission also blamed "the autonomy, pervasive reach and clandestine role of intelligence agencies in Pakistani life" that "underlie many of the problems, omissions and commissions set out in this report".
"Ms Bhutto's assassination could have been prevented if adequate security measures had been taken," the commission said.
It also found that the investigation into her death was hampered by intelligence agencies and other government officials, "which impeded an unfettered search for the truth".
Mr Musharraf's government blamed Baitullah Mehsud, a Pakistani militant commander with reported links to al Qaida, and CIA officials also said Mehsud was the chief suspect. But Ms Bhutto's party repeatedly hinted that Mr Musharraf or his allies were involved and demanded a UN probe.
Faranaz Ispahani, spokeswoman for President Asif Ali Zardari, Ms Bhutto's husband, said: "The UN commission has meticulously identified the criminal attitude of the previous dictatorial regime that led to Mohtarma Benazir Bhutto's death."