A pair of criminologists from Texas State University believe that people who are accused of committing highly publicized crimes are often wrongly convicted because some police officers develop tunnel vision when they decide they have identified the perpetrator. The researchers came to this conclusion after studying the investigative missteps that led to 50 wrongful convictions. Several of the cases were investigated by detectives who either coerced confessions or changed their theory of the crime after being presented with exculpatory evidence.
One such case involved a man who was released from prison after spending 16 years behind bars when DNA evidence proved his innocence. Police investigating the murder of a 15-year-old girl quickly focused their investigation on obtaining a confession from one of the slain girl's classmates, and they changed their theory of the crime instead of pursuing other leads when forensic evidence exonerated him. The man was eventually convicted based largely on a confession that he claimed was coerced and he later retracted.
According to the researchers, police investigations into high-profile crimes are often run to produce a result rather than discover the truth. The Innocence Project has used DNA evidence to overturn 367 wrongful convictions. The wrongfully convicted individual confessed in about a third of these cases. The results of the wrongful conviction study were published in the Northeastern University Law Review.
Some detectives can be highly adept at using the emotional pressure of an interrogation to encourage suspects to act in ways that are not in their best interests. This is why attorneys experienced in criminal defense cases would likely urge clients to remain silent and answer no questions until they have representation available.