The Control Yuan this week ordered a re-examination of polygraph tests conducted by Lee Fu-kuo (李復國), who was the Criminal Investigation Bureau’s polygraph testing expert and who presided over a number of wrongful conviction cases.
Controversy surrounding Lee and his judgements have cast doubt on the reliability and scientific validity of polygraph testing and have led to questions of whether wrongful prosecution arose from human error or unethical conduct.
A Control Yuan committee approved an investigation report on Wednesday looking into the issue and mandated the Executive Yuan open a probe into cases dating back to 1988 as presided over by Lee, who in 2008 retired from his position at the Ministry of Justice Investigation Bureau.
The most prominent conviction that resulted from Lee’s polygraph assessment was Chiang Kuo-ching (江國慶), a 21-year-old who was serving his compulsory military service at an air force headquarters office and who was executed in 1997 after being wrongly identified as the man who raped and killed a five-year-old girl. He was posthumously acquitted in 2011.
Chiang and his family had maintained his innocence and said that he was tortured and forced to sign a “confession.”
Lee was the polygraph expert at the bureau during the investigation and conducted the testing on a number of suspects at the office.
Chiang was reportedly the only suspect who failed the polygraph test administered by Lee.
Air force officials and the military tribunal fingered Chiang as the main suspect and he was convicted of the crime and sentenced to death less than one year after the investigation began.
In another case involving the theft of ammunition at a Taoyuan military base in 1999, officials focused their investigation on three soldiers who reportedly failed Lee’s polygraph tests.
However, tests by another expert from the police agency cleared them.
In 2000, four men were charged over the theft based on physical evidence, thereby clearing the three accused soldiers.
Control Yuan members Wang Mei-yu (王美玉) and Chang Kui-mei (仉桂美), who wrote the report, said their findings cast doubt on the use of polygraph testing in judicial investigations, saying that results can be interpreted subjectively and are prone to human error.
“We found there is no standard procedure and no regulations for polygraph testing. The use of the results in criminal trials infringes on the rights of the accused and violates other human rights issues,” Wang said.