In July, Ms. Chiba approved  and witnessed  the hangings of two inmates convicted of murder, saying she was carrying out her duties as justice minister. Afterward, she said she still opposed capital punishment and ordered that journalists be given a tour of the facilities. She also promised to create a panel of experts to discuss the death penalty, including whether it should be stopped. The panel meets next month.

Japan has long been criticized by human rights activists for its capital punishment system. The United Nations Human Rights Committee, which monitors civil and political rights, has urged Japan to consider abolishing the death penalty, citing the large number of crimes that entail the death sentence, the lack of pardoning, the solitary confinement of inmates and executions at advanced ages and despite signs of mental illness.

Japan also has a 99 percent conviction rate, a figure critics attribute to widespread use of forced confessions. A series of false convictions have surfaced in recent months, including one of a 63-year-old man who had served 17 years of a life sentence for the murder of a 4-year-old girl. He was released after prosecutors admitted that his confession was a fabrication made under duress and DNA tests showed he was innocent. Critics say there is a high possibility that some of those on death row are innocent.

Inmates on death row are not told when they will be executed until the last minute  a procedure Japanese officials say prevents panic among inmates  and their family members and lawyers are informed only afterward, as are the news media.

Inmates can remain on death row as long as 40 years, though executions over the past decade have occurred on average after about 5 years and 11 months on death row, according to the public broadcast channel NHK. The Justice Ministry has refused to disclose how it makes decisions to go ahead with executions.