Though early reports indicated that she had been hit by shrapnel or the gunshots,[8][9] the Pakistani Interior Ministry initially stated that Bhutto died of a skull fracture sustained when the force of the explosion caused her head to strike the sunroof of the vehicle.

[14] After eight years in exile in Dubai and London, Bhutto returned to Karachi on 18 October 2007 to prepare for the 2008 national elections, allowed by a possible power-sharing deal with President Pervez Musharraf.

[21] The Israeli newspaper Maariv reported that Bhutto further asked the American Central Intelligence Agency (CIA), Britain's Scotland Yard and Israel's Mossad several weeks before the assassination to help provide for her protection.

[23] After the assassination, President Musharraf denied that Bhutto should have received more security, saying that her death was primarily her own fault because she took "unnecessary risks" and should have exited the rally more quickly.

[26] According to Getty Images photographer John Moore, Bhutto was standing through her vehicle's sunroof to wave at supporters, and fell back inside after three gunshots.

Rehman Malik, a security adviser for Pakistan Peoples Party, suggested that the killer opened fire as Bhutto left the rally and that he hit her in the neck and chest before he detonated the explosives he was wearing.

[37][38][39] According to an Associated Press report, the Ministry stated "Bhutto was killed when she tried to duck back into the vehicle, and the shock waves from the blast knocked her head into a lever attached to the sunroof, fracturing her skull."

[48] Despite the ambiguity surrounding her death, Bhutto's husband Asif Zardari did not allow a formal autopsy to be conducted citing his fears regarding the procedure being carried out in Pakistan.

[50] On 8 February 2008, investigators from Scotland Yard concluded that Benazir Bhutto died after hitting her head as she was tossed by the force of a suicide blast, not from an assassin's bullet.

However, as quoted in an article in The New York Times: "It is unclear how the Scotland Yard investigators reached such conclusive findings absent autopsy results or other potentially important evidence that was washed away by cleanup crews in the immediate aftermath of the blast.

Foreign outlets, trains, banks and vehicles were destroyed or burned and protesters took over the streets, chanting slogans and setting tires on fire in several cities.

[67] Senator Latif Khosa, one of Bhutto's top aides, reported that she was planning to divulge evidence of fraud in the upcoming election following the event where the assassination took place.

The pair co-wrote a 160-page dossier on the subject, with Bhutto outlining tactics she alleged would be put into play, including intimidation, excluding voters and fake ballots being planted in boxes.

In a statement he made on 1 January 2008, Khosa said: The state agencies are manipulating the whole process, there is rigging by the ISI (Inter-Services Intelligence), the Election Commission and the previous government, which is still continuing to hold influence.

One of the claims in the dossier was that US financial aid had been secretly misappropriated for electoral fraud and another was that the ISI has a 'mega-computer' which could hack into any other computer and was connected to the Election Commission's system.

[39][81] The Interior Ministry also claimed to have intercepted a statement by militant leader Baitullah Mehsud, said to be linked to al-Qaeda, in which he congratulated his followers for carrying out the assassination.

[88] British newspaper The Times suggested that elements within the Pakistani Inter-Services Intelligence with close ties to Islamists might have been behind the killing, and it also asserted that it is unlikely that Musharraf would have ordered the assassination.

The unit, headed by the Chilean diplomat Heraldo Muñoz, found themselves plunged into a murky world of conspiracy theories, power politics and conflicting agendas.

Muñoz was supported by the Indonesian official Marzuki Darusman and Peter FitzGerald, a retired Irish police officer who headed the initial inquiry into the assassination of Lebanese Premier Rafik Hariri in 2005.

The UN was asked to send a team to dispel a conspiracy theory that claimed that Zardari himself had orchestrated his wife's death, a notion most analysts dismissed because of absence of any concrete evidence.

[97] The report stated that "police actions and omissions, including the hosing down of the crime scene and failure to collect and preserve evidence, inflicted irreparable damage to the investigation".

[97] In its report, the UN Commission stated that: A range of government officials failed profoundly in their efforts first to protect Ms Bhutto and second to investigate with vigour all those responsible for her murder, not only in the execution of the attack, but also in its conception, planning and financing.

The collection of 23 pieces of evidence was manifestly inadequate in a case that should have resulted in thousands.... Hosing down the crime scene so soon after the blast goes beyond mere incompetence and needed fixing criminal responsibility on many.

It was patently unrealistic for the CPO to expect that Mr Zardari would allow an autopsy on his arrival in Pakistan while in the meantime her remains had been placed in a coffin and brought to the airport.

The Commission was persuaded that the Rawalpindi police chief, CPO Saud Aziz, did not act independently of higher authorities, either in the decision to hose down the crime scene or to impede the post-mortem examination.

[100][101][102] On 31 August 2017, a Pakistani anti-terrorism court declared that Musharraf was a wanted fugitive due to the role which he played in connection with Bhutto's murder and acquitted five suspected Pakistani Taliban of conspiracy to commit murder due to lack of evidence, while sentencing two high-ranking police officers to 17 years in prison, one for mishandling security at the Bhutto rally and the other for mishandling evidence at the crime scene.

[103][104][105] On 16 December 2019, Musharraf, in exile for hospitalization in Dubai, was sentenced to death in Pakistan in absentia for high treason, for suspending the constitution and imposing a state of emergency a decade early, with right of appeal.

"[108] In a televised address, President Musharraf publicly condemned the killing of Bhutto, proclaiming a three-day mourning period with all national flags at half-mast.

"[116] Bhutto's assassination was met with widespread condemnation by members of the international community,[108] including Pakistan's regional neighbours Afghanistan,[108] China,[117] India,[108][118] Bangladesh and Iran.

[108][118] The United Nations Security Council held an emergency meeting and unanimously condemned the assassination,[119] a call echoed by UN Secretary-General Ban Ki-moon.