The defense counsel had asked the top court to correct its ruling last month upholding the death sentence issued by a lower court.

The top court's four-justice No. 3 petty bench agreed unanimously to reject the objection, in which the defense had asked the Supreme Court to correct the ruling it issued last month, bringing an end to the 43-year-old Miyazaki's 16-year trial process.

In a letter to Kyodo News just before the Jan. 17 Supreme Court ruling, Miyazaki maintained his innocence on grounds of insanity, and said he thinks he "did a good thing."

Throughout the trials, he did not apologize for the slayings.

The Code of Criminal Procedure allows a defendant or prosecutors to file an objection against a Supreme Court decision but limits its scope to minor points, including wording errors. The top court has never changed its decision on focal points.

The four justices agreed in their decision that "no errors were found in the ruling."

The defense team did not reveal which points they wanted corrected.

On Jan. 17, the top court ruled that an extreme character disorder could be found in the defendant, but that he was not suffering from any mental disorder that would make him unable to bear criminal responsibility.

The court said Miyazaki abducted and killed the four girls in Tokyo and neighboring Saitama Prefecture "to satisfy his own sexual desire and appetite to own videotapes with footage of corpses."

The defense council for a convicted serial killer asked the Supreme Court on Thursday to correct last week's decision that upheld a lower court's death sentence against Tsutomu Miyazaki, 43, the lawyers said.

It is unknown which points in the decision by the top court's No. 3 petty bench the defense team wants to be corrected.

The Code of Criminal Procedure allows a defendant or prosecutors to file an objection against a Supreme Court decision but limits its scope to minor points such as wording errors. The top court has never changed its decision on focal points so far.

The death sentence on Miyazaki, who was accused of abducting and killing four girls between 1988 and 1989 in Tokyo and neighboring Saitama Prefecture, will stand if the objection is turned down.

The focus of Miyazaki's trial was on whether he was mentally competent at the time of the crimes.

On Jan. 17, the four-justice panel unanimously ruled that an extreme character disorder could be found in the defendant, but that he was suffering no mental disorder such that he was unable to bear criminal responsibility.

Justice Tokiyasu Fujita, in handing down the decision, said Miyazaki killed the four girls "to satisfy his own sexual desire and appetite to own videotapes that record corpses." He called such motivation "selfish and cruel," adding, "There is no room to consider commuting the death penalty."

The Supreme Court on Tuesday upheld the death sentence for Tsutomu Miyazaki, ruling that one of Japan's most notorious serial killers was mentally competent when he abducted and murdered four girls in the late 1980s.

The top court upheld the Tokyo High Court's sentence, rejected the appeal filed by Miyazaki and thus ended a series of trials that had lasted about 16 years.

The mental competence of Miyazaki, 43, was the focal point in the legal proceedings.

"The high court's ruling that acknowledged he can be held criminally responsible is correct and can be accepted," Presiding Justice Tokiyasu Fujita of the Supreme Court's Third Petty Bench said. "He had killed four girls to satisfy his sexual desire, and there is no room for an extenuation in his inhumane motive. It had a major impact on society."

Fujita said the murder spree was well planned and motivated also by the defendant's desire to collect video footage of dead bodies.

The ruling acknowledged Miyazaki abducted the girls in his car and then strangled them. He groped, videotaped and destroyed their bodies.

"The court has no choice but to uphold the lower court rulings,'' Fujita said.

The death sentence will be finalized unless the defense team files a request to rectify the ruling within 10 days.

Attention to the case grew after Miyazaki began giving incomprehensible testimony, including his claim that a "rat man'' appeared before he killed the girls, and that he ate the wrists of one of the victims.

Maiko Tagusari, a lawyer who represents Miyazaki, said Tuesday's ruling was unacceptable because it ignored evidence that her client has been suffering from chronic mental illness since the time he committed the crimes.

During the trial, defense lawyers said it was "obvious (he) is suffering from some kind of chronic mental disorder, such as schizophrenia."

But the prosecution said: "The psychiatric evaluation that showed the defendant can be held criminally responsible is based on sufficient grounds, and is, therefore, legitimate."

During the Tokyo District Court trial, two psychiatric evaluations were conducted. One group said Miyazaki had a warped personality but could tell the difference between right and wrong and should be held fully responsible.

The second group said Miyazaki was suffering from either a multiple-personality syndrome or schizophrenia, and should be held only partially responsible for his crimes.

The district court accepted the first evaluation and sentenced him to death. The high court upheld that decision.

Miyazaki was arrested in July 1989 after he was caught molesting a 6-year-old girl in Tokyo's Hachioji, about a month after he killed his fourth victim.

He sent a letter and parts of the remains of one of his victims to her family. He also claimed responsibility in the media using a female pseudonym, Yuko Imada.

Investigators found about 6,000 videotapes in his room, some filled with grisly scenes.

Tsutomu Miyazaki was sentenced to death in both the Tokyo District Court and the Tokyo High Court for abducting and killing the girls, aged between 4 and 7, and damaging the corpses in two of the cases, in less than a year