Nearly 150 criminal cases involved the use of handguns last year in Japan, about 20 more than the previous year, according to the National Police Agency.Of the 148 cases, about 84 percent involved gangsters, it said. Twenty-two people in eight prefectures were killed in the incidents -- up five from the previous year. Nine of those killed were not members of the underworld, including a dentist who died after being struck by a stray bullet in the assassination of the No. 2 man of the Yamaguchi-gumi in August at a Kobe hotel.The NPA said the number of people wounded in gun crimes fell to 31, four less than the previous year. Police confiscated 1,225 handguns, about 21 percent fewer than the previous year. The 464 firearms seized from people other than gangsters accounted for about 38 percent of the total, marking the highest ever proportion, the NPA said.