NPR had Glenn Reynolds, author of Outer Space: Problems of Law and Policy on.

Interestingly enough, if a crime is committed aboard the International Space Station, prosecution would depend on which module the crime occurred in, who committed it and whom it was committed against.

A spacewalking astronaut also qualifies as a "spacecraft" under maritime law. So, an attack on a U.S. spacewalking astronaut would fall under U.S. law.