He may present the existing evidence to the offender in a way that makes the guilt appear more certain than it perhaps is, or if he enhances the confidence in the evidence, this could be an effective and acceptable approach to elicit a confession. Coercion and lies, however, should not be an acceptable interrogative practice.
In another case in 1987, detectives lied to Florida resident Thomas Sawyer about the presence of physical evidence at the crime scene. They told the man that they found his hair and clothing fibers on the murder victim's body. After spending 14 months in jail awaiting trial, Sawyer's coerced confession was suppressed and he was exonerated in 1989.
Granted, the ramifications of not finding the murderer are severe. There are two things to consider when dealing with an accused person....
If evidence is not clear and he is the real offender, letting him go risks the possibility of a repeat offense. If he is not the real offender and he is imprisoned without clear evidence then an innocent person is being punished. The second would be crueler. Deception should not be used in order to avoid the possibility of a false confession. Imprisoning an innocent man is more of a crime than not imprisoning a guilty man and therefore, investigators should not force an accused to make a confession that is false.
There are other more reliable ways to prove an accused guilt, which should be exhausted before considerations for interrogative deception should be made. In conclusion, deception should be based on a substantial amount of incriminating evidence and not on clear lies as in the two cases presented above.
