When prosecutors and defense attorneys try a case, one of their top considerations is which witnesses to bring to the stand. Of course, some witness choices are more necessary and obvious than others. For example, if the charge in question is vehicular homicide, then a witness who claims to have seen the incident could be a must-have for the stand and can help prosecutors get a conviction.
Note the “can help,” though, not a “will help.” Not all witnesses are created alike, and some witnesses have problems that affect how prosecutors and defense attorneys handle them.
It could actually be that the problem resides not with the witness but with the setup of the scene: low light, occurrences some distance away, cross-racial identification and so on. In such cases, the witness could be 100 percent accurate about what he or she saw but unless cameras were present and recording, there is really no way to know. If a prosecutor puts someone like this on the stand, defense attorneys may be able to introduce reasonable doubt about what the witness really saw.
How the witness comes across
Some witnesses come across as extremely trustworthy and personable, and in a sense, they can sometimes “get away” with more than witnesses who come across as boring, dry, hostile or somehow negative. Say that the charge in question is phishing. A witness who is able to explain about phishing in layman’s terms and without appearing cocky or dull could have more success with a jury than a witness who may know more but who cannot communicate as well as the other witness.
If you are defending against such a charge, your defense attorney is likely to evaluate several witnesses for factors such as personality and credibility and put the ones who can most help you on the stand. Similarly, if a defense attorney thinks a defendant may not come across well on the stand, there is likely to be advice not to testify.