Cute, Jim. Not funny, but cute.
Tarane, I'm guessing when you created your detective, you didn't acquire either Basic Hair Analyis or Basic Thread Analysis with your starting 20 skill points or whatever you got.
All new detectives start out with basic footprint analysis and basic handwriting analysis as givens in their background. This means they can see all feet and notes, they just can't see specifics about them (whether the footprint is slim or heavy, and whether the handwriting is right- or left-handed). Basic thread and hair analyses, however, must be acquired by everyone. No one gets these as freebies.
So my best guess is your case had some combination of a hair and/or thread. Because you prob'ly don't have these two skills, you can't see the evidence at the crime scene.
The only way to be able to solve these kinds of cases until you get these smart skills is to find the suspects with the false alibis, and then get witness evidence statements (W/E), either one or two of them, on one particular suspect with a false alibi. It's a more difficult route to go, but not impossible.
Hope that helps. Good luck, and Happy Hunting!! ;-)
Once more with feeling:
WE + fake/ no alibi = GUILTY
PE + fake/ no alibi = GUILTY
2 WE = GUILTY
Otherwise, just quit. Don't listen to Jim. Just cause his pupils are dilated doesn't make it cool. Peer pressure is as wrong as a stripper pole with splinters.