The first jury trial for more than 60 years is being held in Japan.
Six jurors are working with three judges to decide a verdict in the case of Katsuyoshi Fujii, 72, who has been charged with murder.
Until now Japanese trials have been decided by a panel of judges. Critics say the old system was too slow, lacked transparency and was out of touch.
The BBC reports criminal trials currently have a 99% conviction rate.
There are increasing concerns that the system of judge-only trials and private police interrogations leads to false confessions and the conviction of innocent people.
The jurors at Tokyo District Court have four days to decide the verdict and, if guilty, the sentence for Katsuyoshi Fujii. He is charged with the fatal stabbing of a neighbour, aged 66, in May.
At least one of three professional judges presiding over the trial must agree with the jury's decision for it to stand.
About 2000 to 3000 jury trials could be held per year, all of them for serious crimes such as murder and rape. About 300 mock trials have already been held in preparation.
Japan has the death penalty, but this is usually given only for multiple murders.
Candidates for jury service will be randomly selected from eligible voters nationwide.
Japan previously introduced a jury system in 1928, but dropped it in 1943 during World War II.