Prior to Saturday's expiration of the statute of limitations on the last crime in the Glico-Morinaga extortion case, the National Police Agency conceded defeat Thursday to the extortion ring. The 15-year statute of limitations on the crime runs out midnight Saturday. It will be the first time the NPA has failed to arrest suspects in a case they have investigated. "It is extremely regrettable that we could not apprehend suspects," NPA chief Setsuo Tanaka told reporters Thursday. "It is indispensable that we make this an important lesson for our future investigations." Four instances of cyanide-lacing of sweets found in Tokyo and Nagoya in February 1985 were the last in a series of crimes related to the Glico-Morinaga case to reach the statute of limitations. Caution and poor coordination between the NPA and prefectural police were to blame for the failure to arrest the extortion ring, said Yuji Aiura, a senior official with the agency's first criminal investigation section. He also said goods left at the crime scenes were mass-produced, making it impossible for investigators to trace the purchasers. "We cannot deny the fact that we had problems with our investigation skills as a police entity," Aiura said. Katsuhisa Ezaki, president of Ezaki Glico Co., told a news conference Thursday in Osaka that he is sorry the case has never been solved. Asked if he has any message for the culprits, Ezaki said he does not want them to repeat this kind of crime. Ezaki said he hid nothing from police, adding that he was not in collaboration with the culprits. "I haven't forgotten the crime entirely, but after 16 years I hardly remember it in my daily life," he told reporters at the company's headquarters in Nishi-Yodogawa Ward. Ezaki, 58, was abducted by three armed men while bathing in his home in Nishinomiya, Hyogo Prefecture, on the night of March 18, 1984. He was taken to a warehouse in Ibaraki, Osaka Prefecture, as part of an attempt to extort 1 billion yen in cash and 100 kg of gold bullion. Ezaki managed to escape from the warehouse three days after his abduction. A series of extortions targeting six confectionery and food firms followed until March 1985. The statute of limitations on Ezaki's case ran out in March 1994. The NPA said approximately 1.3 million officers were mobilized to work on the Glico-Morinaga case. About 28,300 tips were provided to police from the public, and police conducted hearings on about 125,000 individuals, it said. Following the Glico-Morinaga case, 545 similar extortion attempts targeting food producers were reported across the country until last year, it said. Of them, 322 cases have been solved, according to the NPA.