That said, basic police work can still generally track the origin of a drone back to when it was built/sold. Every electronic component has a date code, and there are records of sales all along the way. That can tie it to a location/purchase, in store surviellance can often provide images of buyers, (mail/internet order is even easier) and get back to who had the drone to begin with.
At the end of the day, the higher the tech 'toys' used in a crime the easier it is for law enforcement to figure out who did it.
No doubt. And if you were really trying to be stealthy you would open up an "e-waste" store and use it to collect things which you could scavenge parts out of. (would make for some good fiction as well). Thinks like GPS units are hard to get in junk bags, but easy to pick up at a recycling store out of an old phone (assuming it isn't part of the SOC). But the point remains that all of those things have 'tendrils' and the mosaic effect is very real.
Most of what you need to build an autonomous air vehicle is already in your phone: https://code.google.com/p/andro-copter
What are you going to do, restrict brushless DC motors, LiPo batteries, carbon fiber tubing / ABS plastic, and small propellers (they still use wooden ones on some planes, which would also work on quads) ?
I think the big change has been in the autonomous navigation combined with the pre-assembled stuff that is really hard to crash unless you're trying. For a few grand now, you can get a more or less plug-and-play (or charge-and-fly) system capable of transporting a few pounds of cargo a dozen miles with a minimally trained operator and minimal assembly.
You could also use a big model rocket, but you can't buy a huge one off the shelf that works so reliably with little skill. RC subs would also be possible, but again, you'd need to do a lot of your own R&D, whereas companies like DJI now do it for you. Big RC helis have been capable of the same-ish payloads for a decade or more now, but they're hard to fly, hard to build, and require quite a bit of training to fly without crashing. You'd also need to be watching it every second in flight, unlike the self-stabilizing GPS waypoint systems which have become affordable (<$10k and available to non-military) in the past few years.
GL tracing a drone built from part kits bought of deal extreme or Ebay.
Most of those drones are built from general purpose electronics which even if they were original and no knock off which is very common these days they would've been bought from some reseller in bulk and no one actually tracks individual components.
While i agree that it's easy enough for a detective to go and ask around who has a drone but once you have enough of them flying around that won't be as simple either.
That said, basic police work can still generally track the origin of a drone back to when it was built/sold. Every electronic component has a date code, and there are records of sales all along the way. That can tie it to a location/purchase, in store surviellance can often provide images of buyers, (mail/internet order is even easier) and get back to who had the drone to begin with.
At the end of the day, the higher the tech 'toys' used in a crime the easier it is for law enforcement to figure out who did it.