I dunno - there are often some shocking disconnects in the way people think. There was a case several years ago when a guy had modded his VW Beast (IIRC) with a side-mounted, but inoperative, German WWII era machine gun mount. I’m enough of a jerk to think that this is an amusing thing to do to a car, so long as it can’t be fired. (It was similar to my fantasy when I learned to drive in eastern Mass of mounting a surplus .50 cal MG on the roof of my car.) But I think it would be reasonable to assume that the first time any cop saw that, the vehicle would be pulled over.
So, one might expect that keeping a full-auto modified AK variant with full-sized magazines on the back seat in full view of anyone looking into the vehicle should have raised some flags as being a Bad Idea[sup]TM[/sup] to the driver of this car?
Doesn’t always work My dad, who used to be a police officer, once pulled a guy over because he was driving too perfectly. He told me he’d never seen such perfect, by-the-book driving, and figured something had to be up. So he pulled the guy over, walked up to the car, and asked, “Did your driver’s license expire today?” The driver slumped in his seat, sighed, and groaned, “Yes!” He was actually on his way to get it renewed when my dad stopped him. Dad grinned and sent him on his way. He thought he whole thing was hilarious.
Randy Kraft (the southern California serial killer) who was convicted in 16 murders and thought responsible for 51 more) was caught when cops saw his car weaving over the center line and pulled him over, thinking they had a drunk driver on their hands. They were kind of surprised to find the body of a man Kraft had just strangled in the front seat.
Arthur Shawcross actually was captured as the result of a semi-traffic stop. He made the classic error of returning to the scene of the crime to gloat over the corpse. A state police surveillance helicopter spotted the body and Shawcross, and followed his car back into town where he was taken into custody.
This was a traffic accident rather than a random police stop, but blowing up the Israeli Embassy in Bangkok in 1994.
A small rented moving van collided with a motorcycle at the Chitlom Intersection. Nothing too serious; the motorcyclist was not hurt, at least not badly. This was before cellphones were common (existent?), and the driver of the truck and his passenger walked into Central Department Store on the corner, presumably to phone the police from a pay phone. They disappeared.
When the police did arrive, they towed the truck to the local district police station and parked it on the street out front. They contacted the company that owned the truck. A small company, a two-man operation from the sound of it – the owner told police that two Arab, or maybe just Muslim, men had rented it. His assistant had gone to deliver it but never returned. Seems it was not unusual for his assistant to disappear upcountry suddenly to visit his family, though, so the owner thought nothing of that. May have been close to a holiday, too, I don’t remember, but if so, that would have increased the chances that the assistant would have just taken off.
The truck sat out in front for a full week before anyone thought to look inside the back. They found two (2) items of interest: 1. The dead assistant. 2. Explosives packed to the gills. Seems, too, there was some sort of button up front that could have detonated the load. It was only sheer luck that some cop never pushed it just to see what it did.
The Israeli Embassy is not too far from the US Embassy, but they managed somehow to find out just who the guys were who rented the vehicle, and they were linked to hard-line anti-Israeli activity, plus this was 1994, back when it had not yet become popular to attack US Embassies. So they figured the target was the Israeli Embassy. The traffic accident was not far away, either, and they seemed to be heading in the direction of that embassy. I seem to recall they actually caught at least the main perp in southern Thailand years later.
Neither can English cops generally. But you try proving that you were stopped at random rather than ‘because he was driving erratically’ or ‘his tail light looked faulty’ or whatever else the cops come up with to cover the stop.