Did the Syrian regime kill a British doctor? His mother demands answers

GENEVA - Talks to end Syria's civil war will continue Friday.

The U.N. mediator warned on Thursday that failure is staring the participants in the face, nearly three years after Syrians rose up against the Assad dictatorship.

A sense of the suffering comes from a mother who traveled to Geneva to demand answers to a mystery.

Outside the hotel where the Syrian government delegation is staying Fatima Khan cried for justice.

"Tell me why you killed my son," she called.

She wants to know how her son ended up dead in a Syrian prison.

Dr. Abbas Khan, a British orthopedic surgeon and father of two, traveled to rebel-held Syria to treat the victims of the country's civil war in November 2012. He disappeared two days later.

Last July, his mother made the dangerous journey to Damascus to search for him, while her daughter, Sara, waited in London.

"She went to every diplomatic mission, she went to every official and she revisited these people," Sara Khan said. "She didn't just go once, she kept going back. She sat for hours."

After two weeks, Fatima Khan was summoned to the Ministry of Justice. Abbas Khan was brought in. She barely recognized him.

"He was a skeleton and he started crying and he said 'Mummy, I'm sorry, I'm sorry, please take me from here. I didn't do anything wrong,'" she said. 

 Sara Khan said her brother had marks all over his arms.

"He had skin infections," she said. "She said there were cigarette burns in his feet. He had missing nails."

Fatima Khan spent six long months in Damascus lobbying for her son's release. The Syrian government assured her he would be home soon.

"Oh, it was hope, 100 percent, I thought that he will be released," she said.

But on the day she thought she was taking him home, Fatima Khan arrived at the prison only to be told that her son had committed suicide. She didn't believe it.

"I said 'Sir, say that you killed him, don't say he commit suicide,'" she said.

For Fatima Khan, these peace talks are a chance to confront the Syrian government again.

"I want answers so that I can sleep peacefully," she said. "I can't sleep."

But Swiss police wouldn't allow her to protest on the sidewalk outside the talks, and Syrian government officials ignored her.

"I don't think they will say sorry, but I just want to know how and why they killed him," she said.

Did her son know he was going to be killed? What were his last words?

Those are questions she asks not just for herself, but for tens of thousands of mothers whose sons have suffered the same fate.