EXONERATIONS: Part VII – Misconduct by Police and Prosecutors at Trial Cause of Wrongful Convictions



(This is the sixth in an 11-part series by The Vanguard reporting on a study of exonerations produced by Samuel R. Gross, Maurice J. Possley, Kaitlyn J. Roll, and Klara H. Stephens)

By Linhchi Nguyen 

About 23 percent of all exonerations involved official misconduct in court during the trial, particularly by law enforcement officers and prosecutors, according to the seventh in an 11-part series of an exoneration report conducted by Samuel R. Gross, Maurice J. Possley, Kaitlyn J. Roll, and Klara H. Stephens.

The authors outline the types of misconduct that occurred during 28 percent of trials that later led to exonerations – the most common form of official misconduct at trial was perjury by law enforcement officers, which are usually police officers.

During these incidents, police officers mostly lied about the conduct of the investigations or statements by other witnesses.

For instance, police sometimes lied to make their own observations or conduct appear consistent with statements by other witnesses. This was the case during Steven Dewitt’s murder trial, where a police officer lied about an eyewitness’s testimony regarding the number sequence of a license plate.

The police officer stated that the witness saw the numbers “818” on the killer’s car, matching with Dewitt’s when he was stopped; although 10 years after Dewitt was convicted, defense attorneys discovered that the eyewitness had actually said that the license plates included the numbers “829.” Dewitt was then exonerated in 2004.

The study researchers noted, however, that most police perjury concerned the conduct of investigations. One common aspect of criminal investigations that police lied about was the conduct of interrogations at which innocent defendants confessed.

For example, two detectives, who were testifying in a murder case, claimed that they did not abuse the defendant William Oakes when taking his confession. However, after Oakes was convicted, two fellow detectives admitted that those prior officers told them about beating Oakes, firing a gun three times near his ear, and threatening to pull the trigger at him.

Despite these known cases, data on police perjury is unfortunately limited because it’s usually hidden and often never comes to light.

Study authors Gross et. al. stated that they rarely have access to transcripts of the trials at which exonerees were falsely convicted. Thus, even if it is clear that the jury was misled by false evidence, they are unable to identify which police officers testified or what they talked about.

Police perjury can most likely be identified only if defendants (or their lawyers) raised it as a legal claim, or if an officer testified in a manner that is plainly inconsistent with facts that are now known.

On the other hand, there were also several distinct types of misconduct for prosecutors during trial. Prosecutors commit misconduct when they violate the rules of how they are allowed to conduct themselves in criminal proceedings.

One type of misconduct occurs when the prosecutor fails to disclose and correct false evidence by their own witness. In 1959, the Supreme Court held in Napue v. Illinois that a prosecutor has a constitutional obligation to correct perjury by a state witness even if they did not themselves offer the false testimony.

Yet, prosecutors were reported to permit perjury to go uncorrected in eight percent of exonerations. In almost all of these cases, the prosecution also concealed exculpatory evidence.

Sometimes, the perjury is procured by the prosecutors themselves, law enforcement officers, or the civilian witnesses.

The study noted that lying about deals with the prosecution may be a common form of perjury by government witnesses. However, this could be due to the fact that the prosecutor’s knowledge of the perjury by a witness is unusually easy to detect.

Prosecutors will always know about deals with witnesses that they or their offices entered into, so there is usually no trouble in having to track specific evidence indicating that the prosecutor knew the testimony was false.

Another type of misconduct by prosecutors during trial involves lying in court. This act occurred in four percent of exonerations, although the real rate might be higher.

About half of these courtroom lies occurred in closing arguments despite the rule that lawyers are prohibited from making arguments based on factual assertions they know to be false.

Prosecutors may also commit misconduct in court proceedings without lying, typically during closing statements or on cross-examination. Rules governing these events restrict what lawyers can say. If the defense attorney is prepared and vigilant, violations of these rules can be brought to the attention of the judge and addressed on the spot through objections.

However, many defense attorneys fail to object to arguably improper questions and arguments by the prosecutors. There is little incentive to make an objection that is likely to be ignored, and it may draw attention to a statement that would otherwise go unnoticed, or suggest that the defendant has something to hide. Trial lawyers may also avoid objecting to discourage the opposition from objecting to their own questions and arguments.

Without an objection, it will be difficult to know that this sort of misconduct occurred.

Gross et. al. admit to only knowing about impermissible arguments and cross-examinations if they become subjects of significant disputes, typically on review after conviction. According to the report, they occurred in about four percent of exonerations.

Other improper arguments include when the prosecutor talks about “knowing” with certainty the defendant’s guilt or insists that the defendant is guilty solely because they did not testify or talk to the police. Arguments could also be improper when consisting of appeals to racism, sexism, homophobia, and any higher order.

To sign up for our new newsletter – Everyday Injustice – https://tinyurl.com/yyultcf9

Support our work – to become a sustaining at $5 – $10- $25 per month hit the link:


About The Author

The Vanguard Court Watch operates in Yolo, Sacramento and Sacramento Counties with a mission to monitor and report on court cases. Anyone interested in interning at the Courthouse or volunteering to monitor cases should contact the Vanguard at info(at)davisvanguard(dot)org - please email info(at)davisvanguard(dot)org if you find inaccuracies in this report.

Related posts

Leave a Reply

X Close

Newsletter Sign-Up

X Close

Monthly Subscriber Sign-Up

Enter the maximum amount you want to pay each month
Sign up for