First, Jack won't let you in. So you interrogate him at his doorstep.

know about killing? As much as you, thanks to Sutherland.
Sutherland? know nothing, no real names.
Track Sutherland? unique IP address. No warrant, no IP address.
Look apt? no warrant, no entry.
Own a 44? You know I do, stolen few months back. 35 friends at the party.

Chat with your cop friends and sure enough you get your hands on the warrant. Now you get to Enter the Home.

computer: sutherland 1.132.255.17 14:28. His photo shows the gun.
coke can: fingerprint it. can't take it.
look at bulletin board: nothing to do "he's a fan"
books on desk: book by Sutherland, famous dead guy.

If you try to talk to Jack, he won't talk. Head back to the lab. The prints on the can are too incomplete. OK, head to the cops. You learn the IP address is at the UNLV where they teach criminal justice. And oh look, James Riley graduated from the UNLV Criminal Justice course 10 years ago.

Time to head to the lab!

CSI Crime scene Investigation Walkthrough