Cops know this stuff. They deal with it every day, specialized knowledge really. He might not even know what the parts are, or exactly why it's illegal, but the Sarge told him years ago as a beat cop that strange solder means illegal, and since then he's seen it on dozens of Decker's machines. Just like they always know where perps stash their drugs in a car, how cooperative a witness is gonna be, or can tell just from looking at a crime scene if they're gonna get far or not. They've seen it a hundred times before.

On that note, a Police Procedures check might be in order.

It is, TN 4

So cops check every legal (-looking) cyberterminal to see if they have funny solder (or optical equivalent)?

If not, when do they decide to check? (Besides when the runner is an idiot and says, "Er...that's not my cyberde-...eh, cyberterminal in my lap officer!")

Right. So that detection factor only applies if the cop decides to look, and there's not a roll (per se) to make the officer decide to check?

This is one of those areas where "common sense" and "GM fiat" come into play. If you look like a runner, or the SINless, or shifty, expect up to and beyond an anal cavity search. If you look like you belong, aren't up to anything, and ain't upsetting anything, they probably won't care.

Of course the typical runner wears the black leather trenches, obvious cyber eyes, and looks ready to run and/or rip someone throat out. You might wanna carry your own rubber gloves, for sanitary reasons.

Sanitary reasons. Right. That's why all my PCs carry rubber gloves.