He calls himself Saleh Abubakar and though he had been reluctant to talk to CBS News, Saleh reportedly told CBS that he's been a member of Boko Haram for seven years.
"We go to their school and attack some of soldiers and policemen," he said.
But when asked why his group decided to target schoolgirls, Abubakar abruptly ended the interview, asking for a safer, indoor location. He told CBS News he'd seen the girls three weeks ago, and they were being well cared for.
"Some of them will complain of headache; we have medicine," he said, when asked if any of the girls were sick. We have everything in the place where we keep them."
Asked if any had been sold into marriage, he replied, "We do not marry them."
He said the girls had converted to Islam -- willingly, he claimed. As a result, they'd been spared being sold into slavery, as the group's leader had threatened.
"We didn't make them convert to Islam by force, just by preaching, you understand," he said.
When pressed on whether abducting the girls and forcing them to convert to Islam is the same as forcing them, he said,
"As I tell you, we are not forcing anyone to accept Islam. We are just preaching to them."
He said the girls would be held captive until the Nigerian government released Boko Haram fighters from prison.
"If Allah wish, nothing will happen to them," he said. "But we ask the government if they don't release our brothers, we are not going to release them."
Asked whether the girls will be killed if the government does not release the prisoners, he replied:
"I will not tell you what we are going to do."
Abubakar also told CBS News the abductions had been planned for three months before they happened, and he warned that Boko Haram intends to kidnap more schoolgirls. The group draws its inspiration from al Qaeda, and he claims they have networks around the world, including in America.