John Lott was a colleague of Obama’s at the University of Chicago and has done extensive research on guns.

From CNS News:

In Chapter Three, Mr. Lott discusses gun-control and takes the reader back to his time at the University of Chicago, where he and then-professor Barack Obama spoke on numerous occasions about guns in America.

“I don’t believe people should be able to own guns,” Obama told Lott one day at the University of Chicago Law School.