The sixth American is thought to have been killed while fighting with Shabaab in Somalia. From Minnesota Public Radio:

Troy Kastigar's family received reports of his death within the past week, according to friends of the family. The circumstances of his reported death aren't clear, and the information could not be confirmed by the FBI.

Kastigar's involvement in Somalia is a puzzle in itself. He told his mother that he was going to Kenya when he left the Twin Cities last November.

Somali community members believe Kastigar was part of the last wave of Minnesota men who joined the violent militia al-Shabaab in Somalia. While some of the 20 or so men say they left to defend their homeland in a bloody civil war, Katigar's motivations are less clear.

Kastigar was unlike the five other Americas killed while fighting in Somalia. The five others had been born in America to Somali immigrant parents. Kastigar's parents were American-born, and he is a convert to Islam.

Kastigar converted to Islam about three to four years ago, a source in Minneapolis told me on Friday. He was married to a Somali woman for several years, but later divorced. He attended the Abubakar As-Saddique Islamic Center, the same radical mosque in Minneapolis attended by other Somali-Americans who have gone to Somalia to fight with Shabaab.