Relatives lie to protect their family!

            I have always been interested in the role psychology plays in the criminal justice system. The whole concept of having a group of random people decide the fate of a defendant in a court of law is intriguing. What sorts of a factors during the trial will persuade a jury member of guilt or innocence? Witnesses play an important role by providing testimony to the jury. But can we believe everything that is said on the witness stand? Some witnesses come across more believable then others, and psychologists are curious to examine what factors play a part in a witness’s credibility. 

            A specific kind of witness that can be the most effective in helping a defendant get a not guilty verdict is an alibi witness. An alibi corroborating witness in a criminal case tells the court an account of the person’s whereabouts and activities at the time that the crime occurred. These witnesses could be blood related relatives, relatives by marriage, friends, or even strangers and acquaintances. A study in 1986 done by Lindsay and colleagues found that conviction rates were significantly reduced when an alibi witness was not a relative. This showed that jurors might be skeptical of relatives who serve as alibi witnesses.

            Harmon, Culhane, Jolly, Chavez, and Shaw (2011) did a series of studies to explore the relationship between an alibi witnesses and defendants and mock juror’s evaluations of the alibi testimony. In their study they looked at to what degree a mock juror thought an alibi witness would lie for the defendant. As expected mock jurors were the most skeptical of biological relatives then relatives by marriage and they were the least skeptical of alibi witnesses who were not at all related to the defendant. They even asked the mock jurors if they would lie to protect defendants. They found that mock jurors were more willing to lie for biologically related defendants.

            One surprising finding is that the skepticism toward witnesses who are biologically related to a defendant was greater than skepticism towards what that witness actually had to say.  The situation that presents itself here is quite ironic. Jurors tend not to believe alibi witnesses whom the defendant is closest too, even though the defendant is likely to spend most of their time with the people they are closest too, especially family members. This presents trouble for defendants who find themselves relying on close family members for an alibi.

            There is one pretty big weakness in this study with the mock jurors. These jurors did not deliberate with anyone when making their decision about the believability of the witnesses. One of the biggest parts of being on a jury is deliberating with the other members of the jury, which could change the outcome of a jury member’s decisions about witness credibility.

            So you may be thinking that the results of this study seems quite obvious, of course people are more likely to lie for their family members rather then a stranger at a grocery store. Although, the strength of the data is quite impressive and this part of the legal system could completely change the fate of a defendant. Defense and prosecuting attorneys also must keep this in mind when dealing with alibi witnesses who are closely related to the defendant. Prosecuting attorneys need to utilize the juror’s skepticism during a trial by hitting home the point that the alibi witness is likely to lie to protect the defendant if they are close. The defense attorney may need to try to get multiple witnesses so they don’t have to rely on just one closely related witness.

            So what does this information mean to you? Well if you are planning on robbing a bank anytime soon having your brother cover for you in a court of law claiming you were just watching TV probably wouldn’t get you off the hook. I recommend paying a stranger before the incident saying you were helping them find their dog or something. But most likely this information will only come in handy on jury duty. When on jury duty remember that although closely related alibi witnesses may very well be lying, listen to the testimony and try and see how believable the things they say are rather then just disregarding them based on their relationship to the defendant! 

 - Anna Teeter

Harmon, M.H., Culhane, S.E., Jolly, K.W., Chavez, R.M., Shaw, L.H. (2011). Effects of an alibi witness’s relationship to the defendant on mock jurors’ judgements. Law and Human Behavior, 35, 127-142.