Policing in Afghanistan is unpredictable. In Pul-i-Alam, Syed Mahboob was arrested, questioned, then released by the same provincial police commander, Abdul Hakim Ishaqzai, who first recommended our trip to Baraki Barak. Ishaqzai explained the problem to me as I sat on a sagging, overstuffed sofa in his large fluorescent-lit office at his provincial headquarters. There simply was not enough evidence against Mahboob to file charges, so they had to let him go.

A month after our last visit to Ishaqzai’s office, Taliban suicide bombers stormed the compound. Ishaqzai was away, but the attack killed more than 20 of his men, many of whom were eating lunch in the cafeteria, the most devastating single assault on the police in more than a year. Soon afterward, Qasim stopped answering his phone. I called Ishaqzai. What happened? He said officials from the Interior Ministry in Kabul had arrested Qasim. They suspected that he was involved in the assault.

The ministry, Ishaqzai explained, had accused three of Qasim’s closest lieutenants of using Qasim’s car to drive the suicide attackers through the initial police checkpoints around the compound. In another startling development, Farhad had also accused Qasim of colluding in the assassination of his brother. A group of officers from Kabul and Pul-i-Alam arrested Qasim and the three lieutenants in Baraki Barak on Feb. 23, the day Qasim stopped answering my calls.

He was in Pul-i-Alam now, under the supervision of the police and the National Directorate of Security. The prosecutor had not filed charges, but Ishaqzai told me that in Qasim’s bedroom, the police had found a kind of wiring that was often used to make improvised explosive devices and a tracking device used by insurgents that tells them when a car is approaching.

The thought that Qasim could be guilty of these crimes was jarring, to say the least. He had hosted us in his district, where we slept, ate and traveled with him and his men into the unmapped depths of the district for a full week. It was hard to imagine why, if Qasim was working with the insurgents, he had not tried to kidnap me and Tyler Hicks and sell us to the Taliban. He could have easily staged an incident with the insurgents. Hicks and I asked him shortly after we arrived whether we could spend the night in a remote outpost with the local police; arranging a kidnapping there would have been easy. Qasim refused to let us, though. He said it was too dangerous. The insurgents had even kidnapped his son, back when he was the head of counternarcotics in the district.

And yet truth in Afghanistan, where allegiances shift on a daily basis, is never easy to pin down. Could Qasim have helped killed Khalil? Could he have facilitated the murder of more than 20 of his fellow officers in Pul-i-Alam? Just as his true motivations were unknowable, so, too, were the motivations of those who accused him. Arrests for political reasons occurred all the time. The police and the intelligence service were interrogating him now, and they could just as easily release him as charge him with murder. As Mahboob’s father told me, the police had also arrested Mahboob again, just 10 days after they released him, and on the same charges.

Ishaqzai said he couldn’t tell me much else. He wasn’t in charge of the investigation, but he doubted that Qasim was involved in Khalil’s death. He was less certain about whether Qasim could have helped the insurgents attack the Pul-i-Alam headquarters. Such things happen, Ishaqzai said. He had known Qasim well, considered him his finest police chief. But, he reminded me, “people can change their minds in minutes.” Ishaqzai had already replaced Qasim with a younger chief from a neighboring district, he told me before we hung up.

I wanted to hear someone defend Qasim, or reflect the camaraderie and loyalty I thought I saw when I was there. I called Sabir Khan, his good friend and deputy, his most esteemed colleague. Khan told me that the men in Baraki Barak didn’t know how to feel. Even he wondered whether Qasim was involved in the Pul-i-Alam attack. You never know, he said. “I cannot trust him now.”