SAGAMIHARA, Japan (AP) -- A young Japanese man went on a stabbing rampage Tuesday at a facility for the mentally disabled where he had been fired, killing 19 people months after he gave a letter to Parliament outlining the plan and saying all disabled people should be put to death.

When he was done, Kanagawa prefectural authorities said, 26-year-old Satoshi Uematsu had left dead or injured nearly a third of the almost 150 patients at the facility in a matter of 40 minutes in the early Tuesday attack. It is Japan's deadliest mass killing in decades. The fire department said 25 were wounded, 20 of them seriously.

Security camera footage played on TV news programs showed a man driving up in a black car and carrying several knives to the Tsukui Yamayuri-en facility in Sagamihara, 50 kilometers (30 miles) west of Tokyo. The man broke in by shattering a window at 2:10 a.m., according to a prefectural health official, and then set about slashing the patients' throats.

Sagamihara fire department official Kunio Takano said the attacker killed 10 women and nine men. The youngest was 19, the oldest 70.

The suspect calmly turned himself in about two hours after the attack, police said.

Uematsu had worked at Tsukui Yamayuri-en, which means mountain lily garden, from 2012 until February, when he was let go. He knew the staffing would be down to just a handful in the wee hours of the morning, Japanese media reports said.

The facility employs more than 200 people, including part-timers, with nine of them working the night of the attack, Hirosue said. All those killed were patients.

In February, Uematsu tried to hand deliver a letter to Parliament's lower house speaker that revealed his dark turmoil. It demanded that all disabled people be put to death through "a world that allows for mercy killing," Kyodo news agency and TBS TV reported. The Parliament office also confirmed the letter.

Uematsu boasted in the letter that he had the ability to kill 470 disabled people in what he called was "a revolution," and outlined an attack on two facilities, after which he said he will turn himself in. He also asked he be judged innocent on grounds of insanity, be given 500 million yen ($5 million) in aid and plastic surgery so he could lead a normal life afterward.

Some people in the area said they were shocked that Uematsu is accused, and described him as polite and upstanding.

Mass killings are rare in Japan. Because of the country's extremely strict gun-control laws, any attacker usually resorts to stabbings. In 2008, seven people were killed by a man who slammed a truck into a crowd of people in central Tokyo's Akihabara electronics district and then stabbed passers-by.

In 2001, a man killed eight children and injured 13 others in a knife attack at an elementary school in the city of Osaka. The incident shocked Japan and led to increased security at schools.