Psychology of Criminal Justice

Because of the availability and use of highly technical forensic testing methods such as DNA, it has been determined that thousands of innocent people are falsely convicted of crimes every year (Wise & Safer, 2004).  This fact brings into question the reliability of eyewitness testimony, which in the past has led to successful convictions in many criminal cases.

Major Issues to Consider

The fact has been established that innocent people are falsely convicted with alarming frequency in the absence of definitive scientific exclusion as criminal suspects, and that eyewitness testimony is often a powerful conviction tool.  Moreover, eyewitness testimony has been shown to sway juries and influence judges in their rulings during criminal cases.  Likewise, it is reasonable to assume that the reliability of eyewitnesses is not infallible, and eyewitness perception has been shown to be altered by the presence of a weapon in the commission of a crime, stress during the event, and the tendency to forget important details over time, among others (Wise & Safer, 2004).

Victims may also give incorrect eyewitness testimony due to their own mental/emotional instability.  Therefore, in the US, the requirement of two reliable eyewitnesses before said testimony is admissible as evidence has been invoked in key criminal cases over the years (Jain, 2001).

The mental capacity of the accused is also a key consideration in that eyewitness testimony should not be the be all and end all in establishing the guilt of a suspect; rather, the sanity of the suspect must still play a part in the criminal process if the right to a fair trial is to survive and continue (Birch, 2000).


Ultimately, based on the literature reviewed as well as the needs indicated as a result, it is possible to make some recommendations.  Given that expert testimony regarding eyewitness is rarely permitted in Australia, I would like to make the contrarian recommendation that testimony regarding eyewitness be permitted in Australia, under the following criteria:

Utilization of the Two-Witness Rule. Because of the possibility/tendency for witnesses to make an erroneous identification of a suspect or to mistake the fundamental facts of an event, two witnesses should be corroborated before the testimony is considered valid.

Verification of Credibility of Eyewitnesses. Especially in capital cases, it should be determined that the eyewitnesses are in fact of sound mental capacity and that they are not in some sort of collusion to falsely impeach a suspect.Mental Capacity of the Accused. Suspects in criminal cases, even in the event of verifiable 2 eyewitness testimony, the accused should also be determined to be of proper mental faculty to stand trial for the charges.