The murder of Jon'Benet Black

In order to express an opinion about the possible murderer to your superior in a formal letter, you can do these:

1) You should read the evidences brought to you carefully and take notes of the flow of your mind while examining the papers and contemplate about the case.

2) You should prepare a summary about who might have killed the girl.

3) If you have a prediction about the murderer, you should prepare a final draft including your top 3 arguments in a formal tone. If you haven't come up with someone, you can also mention your 3 arguments either accusingly or not.

*Don't forget that you'll be sending only your final draft to your superior.