I also think the 10-20 years could only happen if they actually can only prove one of the murders.Who knows could that happen?It took them a long time to charge him with the other murders,he got charged with Mark's murder right away...as hard as it is to believe maybe they only have strong evidence in Mark's case.....maybe there really was a perry mason style set up.....this is purely fiction of course and I do not think that's what happened but it would make for a good plot I think:
...what if Debra's research came up with something that Farmville and Chi couldn't let come out in the open,that's why she could not return to the university....maybe something like a secret immigration/citizen holding facility and of course Farmville was gathering everyones data through the farmville facebook/myspace app....anyways Farmville had to get rid of Debra and saw Sam's visit as a perfect opportunity,when they came to do the "welfare" check they actually murdered Debra,Emma and Mel and gave Sam instructions to call Mel's mom to tell her they were at the movies and the car broke down ,Sam called the police shortly thereafter hoping the "real" police would come,instead it was the same guys and he knew he was screwed....they told him to stay put until it was time to take his regular flight out and that they would arrest him at the airport or they would kill him like the others.When Mark came to check on his family Sam was freaked out and thought it was one of them coming back and killed Mark....he freaked out and called Sinister to tell him everyone was dead....etc..ok I'll stop,getting carried away again....I hope Dan Brown doesn't read here,lol...