A former Tokyo police officer was sentenced Oct. 17 to three years in prison for trying to frame two innocent men on drug charges in April in conspiracy with two colleagues, who earlier received suspended terms.Nobuji Kawaguchi, 40, listened calmly as presiding Judge Toshiyuki Kosaka described his crime as "unethical," saying he forgot his duties as a policeman. Kawaguchi was a senior officer when on April 9 he illegally received about 1 gram of stimulant drugs from a friend, Satoru Ohara, 33, and conspired with the two other officers to frame someone on drug charges in a bid to boost their job performance records, according to the court.On April 14, Kawaguchi and colleague Masahiko Yamazaki, 37, planted the stimulants in the bag of a 57-year-old homeless man near JR Kameido Station in Koto Ward. The man was taken to the police station but was released without arrest.After failing in their first attempt to frame someone, Kawaguchi had Ohara lure his acquaintance, a 41-year-old factory worker, into a restaurant parking lot in Koto Ward on April 18, where Ohara planted 0.3 gram of stimulants in the man's car. Kawaguchi and colleague Ryoichi Akamatsu, 25, then arrived at the scene to question the man, leading to his arrest for drug possession, the court said. The man was detained for 13 hours at the police station before being released following investigations by other officers. Both Yamazaki and Akamatsu were given 30-month prison sentences, suspended for four years.