Sentence 1: In the police line up, Mark was getting nervous. 
 Sentence 3: When he was called to step forward he stumbled a little 
 Sentence 4:  The witness from behind the glass was not paying attention though 
 Sentence 5:  In the end, Mark was able to get away with his dastardly deed 
 Given Sentence 2: He was guilty of the crime but trying not to show it.