Forensics take home quiz..people who have seen "Murder by Numbers"?

Please help me. I have questions that I need to answer for school, and it counts as a test. Please answer as many as u can. THANK YOU!

1.What is the significance of the title?
2.Why cut off a finger? What is the significance? What were the characteristics of the profile for the killer did the boys try to show?
3.Why would the Vigi shoeprint be helpful?
4.How did the boys set up Raymond Lee Feathers for the murder of Olivia Lake?
5.What is the significance of the sprinklers and the footprints in the house from the planting beds?
6.How many crime scenes were there? Describe each. Did it take all of them to solve the crime?
7.Who manipulated who to kill Olivia Lake?