The search found a gun with obliterated serial numbers in pillowcase. Not usually present in a law-abiding household.
But, bad ID, bad search. Not passing on exculpatory evidence should get the cop fired, and his spending a month in jail would be a wholesome example for other cops.
The cop in question is just as much a scumbag as the yute.
Quis custodiet ipsos custodes?
Spending five years in jail for hiding exculpatory evidence would be a far stronger example to other LEO to stay on the straight and narrow.