A Taiwan court has sentenced a retired soldier to jail for 18 years for the rape and murder of a five-year-old girl, more than a decade after another soldier was wrongfully executed for the crime.

Taipei's District Court said Monday it would have imposed a stiffer sentence for 35-year-old defendant Hsu Rong-chou, but said evidence showed he was mentally impaired.

Hsu's arrest early this year followed a rare admission by Taipei that the wrong person was executed for the crime 14 years ago. That suspect, Air Force Private Chiang Kuo-ching, was convicted and put to death in 1997 at age 21 largely based on a guilt statement that authorities later admitted was extracted by investigators who used torture to gain the admission.

The government later compensated Hsu's family $3.4 million for the wrongful death, and President Ma Ying-jeou issued a formal apology to Chiang's family.

The case spawned intense scrutiny and criticism from death penalty critics, who argue that many of those executed in the country have been wrongfully convicted.