Polygraph Testing in Police Investigations

Ms Faizah Jamal asked the Deputy Prime Minister and Minister for Home Affairs (a) whether the police requires victims of alleged crimes in general and alleged rape or sexual assault crimes in particular, to undergo polygraph testing as a matter of standard procedure; and (b) if so, what use is made of the results of such polygraph testing.

Mdm Speaker, polygraph examination is one of the tools used by Police to support investigation of different types of cases, including sex-related offences. Police will evaluate on a case-by-case basis the value of administering polygraph examinations to persons involved in an investigation, to assess the veracity of the persons' statements and to establish new leads. So, it is not a

Page: 13

standard procedure.

Generally, this is used when there are conflicting accounts provided by the persons involved, and all other investigative leads have been exhausted.

Polygraph examination is voluntary and written consent is required from the subject. During the investigation, Police may request persons involved in the case, such as accused persons, victims or witnesses, to undergo a polygraph examination. Police will explain the nature and process of polygraph examination to the subject prior to it being administered.

Since its introduction in 1991, Police have used polygraph examinations in a relatively small number of cases. Between 2011 and 2013, Police administered an average of 700 polygraph examinations per year, in about 1%-2% of all crime cases that were reported.

Two points of clarification if I may. I thank the Minister for saying that it is a voluntary procedure. That being the case, would there be any consequences if a victim was actually asked and then not want to do so, even though I understand that it was meant to be voluntary?

Secondly, considering the fact that there has been international scientific scepticism about the effectiveness of the polygraph procedure, are there plans to review the use of such a method, in other words, not to have it at all?

Madam, if by "consequences" the Member means whether investigations would somehow be ceased or compromised, the answer is no. The Police will conduct the usual slew of investigations and, as I have said, this is really in order for them to be able to use a different technique, if, in fact, all other leads have not yielded results and there is a need to do so in order to establish the facts in a comprehensive way.

As for international practice, in fact, the opinion is varied on this. The practice of polygraph examinations in some countries is even admissible in Court. In Singapore, that is not the practice. But as an investigation technique, it is not uncommon internationally for it to be used to aid investigation officers in their work.

Page: 14