The Tokyo District Court on Thursday sentenced a Japanese Red Army member accused of attempted murder and other charges to 12 years in prison over a 1986 mortar attack on the Japanese Embassy in Jakarta.

Tsutomu Shirosaki, 68, was one of six inmates who were released from a Japanese prison in 1977 in exchange for hostages from a Japan Airlines plane hijacked by the radical group.

During the trial, prosecutors insisted that fingerprints collected from the hotel room from which the rounds were fired matched those of Shirosaki, but defense lawyers argued that Shirosaki was in Lebanon at the time of the attack and the investigative authorities may have tampered with evidence to incriminate him.

Prosecutors requested a 15-year prison term for Shirosaki.

According to the indictment, Shirosaki conspired with an unnamed person in firing two mortars toward the Japanese Embassy from the hotel room in the Indonesian capital on May 14, 1986, and he used another person’s passport at a hotel and car rental company.

No one was hurt in the attack as the bombs did not go off.

He was imprisoned in the United States over a 1986 rocket attack on the U.S. Embassy in Jakarta after he was captured in Nepal in 1996.

In 2015, Shirosaki was deported from the United States and was arrested on his return to Japan by Tokyo police for attempted murder and other charges over the 1986 attack on the Japanese Embassy.

It was the first lay judge trial involving the radical group.

The Japanese Red Army was formed in 1971 and known for carrying out a series of terrorist attacks around the world, including a shooting rampage at Lod Airport in Tel Aviv, Israel, in 1972 which resulted in about 100 deaths and injuries.

The extreme left-wing group was led by Fusako Shigenobu who was arrested in Japan in November 2000 and remains in jail. Seven fugitives are still on the international wanted list.