Final answer:
Eyewitness misidentification is the leading cause of wrongful convictions, as evidenced by the work of the Innocence Project and cases like Ronald Cotton's. Suggestive police identification techniques contribute to this problem, despite the core legal principle of the presumption of innocence.
Step-by-step explanation:
The most common factor that led to the wrong person being convicted of a crime, as investigated by organizations like the Dallas County Conviction Integrity Unit and noted by the Innocence Project, is eyewitness misidentification. This erroneous element of human memory can be significantly influenced by suggestive police identification procedures, where lineup methods or affirmations by law enforcement can impose certainty on eyewitnesses where doubt previously existed. The reliability of eyewitness testimony thus becomes questionable, as highlighted by numerous cases, including that of Ronald Cotton, where DNA evidence was instrumental in exonerating individuals who were wrongfully convicted. In the broader context of legal justice, the presumption of innocence remains a fundamental principle, yet is often compromised due to public perceptions influenced by media portrayal and preconceived notions of guilt.