Thomas J. Kelly won the Pulitzer in 1979 for his series "Tragedy on Sanatoga Road." The picture that the Newseum has is of Richard Geist, the man who had held his family hostage before killing his pregnant wife. He had just broken loose from police custody. There is a description of the story and a brief bio of Kelly here
. It's from a TNT special called "Moment of Impact: Stories of the Pulitzer Prize Photographs." The site has another photo from the series of the daughter who escaped being carried by a detective.