A 30-year-old man's death sentence for the 2011 murder of a woman in Okayama has been finalized after he dropped his appeal, a branch of the Hiroshima High Court said Friday.

Koichi Sumida, who was sentenced to death in February by the Okayama District Court for killing his former colleague, Misa Kato, 27, a temp staff worker, submitted a document stating he was dropping his appeal Thursday night to Okayama Prison's warden, who accepted it, according to the Okayama branch of the high court and his lawyer.

The lawyer had appealed the Okayama District Court sentence handed down on Feb. 14 in a lay judge trial.

The district court ruled that Sumida, on Sept. 30, 2011, robbed Kato of about ¥24,000 in cash and personal belongings at a warehouse in Okayama where they worked.

He then sexually assaulted Kato, stabbed her to death, dismembered her corpse and dumped her remains in the city of Osaka. The district court sentenced him to death, saying he "was self-centered as he committed the cruel crime to work off sexual frustration" and was not likely to be rehabilitated.