Musharraf has been in self-imposed exile in London and Dubai after leaving Pakistan in 2008. In August 2012, Pakistani authorities confiscated his property and froze his bank account. The former military ruler has denied having anything to do with Bhutto's killing.
Bhutto survived an assassination attempt in October 2007 in Karachi during her homecoming that killed 139 people. The following December, she was killed in a gun-suicide bomb attack as she was wrapping up a campaign rally in Rawalpindi ahead of parliamentary elections.
Mehsud, the alleged architect of the attack, was killed in a U.S. drone strike in August 2009 in Pakistan's volatile Waziristan province, according to authorities. He denied being behind the attack on Bhutto, according to statements released by his spokesman shortly after the former prime minister's killing.
But authorities said Mehsud chose a teenager from his own tribe to act as the as the suicide bomber in the attack on Bhutto.
The suicide bomber was taken to Rawalpindi by three members of the Taliban, who handed him over to two others who provided him temporary housing and gave him information on when and where Bhutto could be targeted, according to Ali, the special prosecutor.