Why do wrongful convictions occur in Capital cases?

Why do wrongful convictions occur in Capital cases? 

A comprehensive explanation is warranted to illustrate at least three reasons why these erroneous convictions occur. 

• One comprehensive and concise paragraph will answer the question properly
• One paragraph and three subsections will reasonably  respond to the multi-dimensional question 
• Grammar and diction are important
• Post  two additional required  comments to  two other students, it will promote a holistic learning approach to the topic discussed
• The class text is a good source to use to support your opinions