FBI figures indicate 391 killings by police were ruled justifiable in 2007, the most since 1994, while last year's 254 killings by private individuals found to be self-defense were the most since 1997, USA Today reported Wednesday.
Analysts say part of the reason for the increase is that police are arming themselves more heavily to counter greater firepower wielded by criminal gangs, while private citizens are taking advantage of state "right to carry" laws.
James Alan Fox of Northeastern University told USA Today the figures show an emerging "shoot-first" mentality by police and private citizens, saying, "Clearly there is a message out there that citizens may be able to defend themselves."
Alfred Blumstein, a Carnegie Mellon University criminologist, told the newspaper that the gun "legalization movement" may have helped create a "greater willingness" to kill people in self-defense.
The National Rifle Association, however, disputes that, saying it is events such as the Sept. 11, 2001, terrorist attacks and the looting after Hurricane Katrina that have prompted some to take more responsibility for their own safety.