this one was silver, like the one seen following jason mcguigan the afternoon before the murders. was the owner's manual for a glock 9 millimeter pistol, like the one missing from jason's apartment, the same caliber weapon used in the murders. ballistic expert bill newhouse compared the shell casings from the murder scene to the ones provided by the manufacturer when jason purchased the weapon. >> it was clearly printed as having been cartridge casings fired in and it specified the glock pistol, which had been fired in with the serial number and really nice information that we don't see very often. >> they matched, proving that it was jason's own weapon that killed him. hoping to find the murder weapon, police searched the garbage dumpster behind mark wu's apartment. instead, they found a pair of sandals in a white plastic bag, along with some of mark wu's credit card receipts. police also checked other dumpsters in a four-block radius. >> they find out specifically where that particular garbage would be dumped, and they dig. and they do that dirty work that so often is the key to