Solve-the-crime book where the answers are on the other page

[Jillian]

There were two books by the same author. There is a detective and his crew, and they solve crimes. They lay out the evidence and what they see, and the detective always figures it out, and then you try yourself. There is an explanation later on. One case involved a body turning into soap and floating in the water. Another involved a woman faking her own death, but being found out because there were traces of sunscreen in the car and none on the burned body. Another was a case where a guy fell and hit his chest and head. The two different colors of blood (oxygenated and deoxygenated) made the detectives believe that two people were involved in a fight. One book had red on the cover, and the other had green. I read this around 2008-2009, in my class. I found them at a library that same year, and haven't seen them since.