HAGATNA, Guam » A Guam man convicted of killing three Japanese tourists in a crash and stabbing rampage last year was sentenced Thursday to life in prison.

Guam Superior Court Judge Anita Sukola sentenced Chad DeSoto to three life sentences to be served concurrently. DeSoto won’t be eligible for parole, Sukola said.

The judge said a life sentence for the 22-year-old man was needed to protect the public. Sukola also said DeSoto failed to show remorse in his statement to the court.

The tourists killed were 81-year-old Kazuko Uehara and 29-year-old Rie Sugiyama, who were stabbed to death; and Hitoshi Yokota, 51, who was hit by a car and died in a hospital two days later. Another 11 people were injured, including two children.

Sukola also sentenced DeSoto to 15 years in prison for the attempted murder of 11 people. DeSoto received the maximum penalty allowed for each conviction.

Yasuhiro Uehara, whose daughter and mother-in-law were both killed in the Feb. 12, 2013 attack, said the perpetrator would have been sentenced to death in Japan.

"I’m very sorry this is not Japan and the punishment is not available here," Uehara said through an interpreter.

DeSoto, who was dressed in blue jeans and a prison-issued orange T-shirt, had pleaded not guilty by reason of mental illness. His lawyers argued he spiraled out of control into psychosis after his grandfather died and his girlfriend moved to Utah.

He read a three-page letter in court asking for mercy which cited biblical verses from St. Paul on faith, hope, and love.

DeSoto’s eyes welled up as a family member read a statement from his mother asking the judge for "forgiveness and mercy upon all of us."

Prosecutors argued DeSoto planned the attack, targeting victims who resembled or symbolized his girlfriend, who had recently dumped him.

The rampage rocked the small island U.S. territory and raised questions of tourist safety in Japan and elsewhere. Guam’s economy depends heavily on tourism.