The man who assassinated Afghanistan’s former-president-turned-peacemaker used an audio recording of a Taliban representative and the promise of a letter from Taliban leaders to set up the meeting in which he killed Burhanuddin Rabbani, according to Afghan officials.

The new details on how the bomber managed to convince Afghan officials to let him see Rabbani suggest he had direct access to the Taliban leadership council before he carried out the assassination. Today, Afghanistan’s intelligence service used that information to suggest a political end to the war may not be possible – a suggestion echoed by the US’ ambassador in Kabul. Rabbani’s death “raises very serious questions as to whether the Taliban and those who support them have any real interest in reconciliation,” Ambassador Ryan Crocker said.

It’s not clear if that means the Afghan government or the United States will stop pursuing negotiations with the Taliban. U.S. officials have met a handful of times with a man they hoped was an emissary from the Taliban leadership council, but those talks have stalled, the officials say.

Before the fatal meeting, the bomber had met with Afghan officials at least half a dozen times, earning their trust and piquing their interest enough for them to call Rabbani to Kabul from a trip to Iran for an urgent meeting, Afghan officials say. President Hamid Karzai today said he too had heard the audio recording that the bomber provided, which included “a couple of questions and suggestions mentioned regarding peace,” Karzai said.

Afghan and US officials working on reconciliation have been hoping the Taliban would provide a list of demands that could jump-start negotiations, and it seems they believed this man could be the one to provide that list. In addition to the audio recording – from a brother of a former deputy Taliban minister – the bomber also said he had a letter that he needed to personally hand over to Rabbani. Afghan officials recovered the blood-stained “letter” from the bomber’s pocket and say it was clearly a fake, including grammatical mistakes that a native speaker of Pashto — the language spoken by Taliban’s leaders — would not make.

Kabul’s diplomatic area is under heavy security today. Rabbani will be buried tomorrow, on top of a hill where the Soviet army built an Olympic-size swimming pool (though never filled it with water) and where the Taliban used to execute their political enemies.