The creepy local shop.

I live in London. On a busy bus route, and a 15 minute walk from one of the busiest train stations in the country. We're not short of shopping choices in the local area.
There's a choice of 4 major supermarkets (and an M&S foodhall) within about a mile of the house, and the normal London abundance of newsagents and smaller shops.
So today, I volunteer to run out and buy some bread so the boss's sickly husband can eat dry toast (I swear to god, if he passes on the vomiting bug I've managed to avoid getting directly from child no.1, I shall kill him with my bare hands.)

Me: *grabs jacket, handful of small change, heads for the front door.*
Boss: Where are you going?
Me:......erm.... Tescos? To get bread?
Boss: Why are you going to Tescos? Go out the back door, go to the corner shop, it's half the distance.
Me: Oh... yeah.... I guess so. But the corner shop scares me.
Boss: scares you?
Me: Tescos fine. Really. I'll go there.
Boss: How can the corner shop scare you?
Me: It smells funny and it creeps me out. And I don't trust it.
Boss: .............
Me: *sigh* Ok. I'll go. But I don't trust it....*walks to corner shop*
Approaches corner shop while on phone to sister...So, yeah, I thought I'd call, I've got a minute, just been sent off to the shop. I'm going to the tiny one I don't like, it smells funny.
Sister: How can you not like it? It's just a shop.
Me: Yeah, well, it smells, and there's..... a.... flashing...light.... SEE!!!! There's a police car outside. Something has happened in the area around the weird shop. Wait...2 cars.... I wonder why they're..... oh.. the shutter on the shop is half down...
Policeman: Sorry love, it's closed right now.
Me: *rolls eyes, turns for home, it starts to rain.* I KNEW IT WAS DODGY!!!!!!

I'm now wondering if that funny smell was a dead body hidden under the floorboards all this time.
What else warrants 2 police cars and 6 policemen in a corner shop in a nice family area of London?
Surely if it was a burglary, it only takes one policeman (if any bother showing up) to take a statement (that'll be filed away never to be seen again).

The other problem with not going to Tescos, is the fact that galaxy chocolate is currently £1 in there, and I was wearing clothes that I could smuggle it home in. The quest for toast was cancelled, and I'm now feeling deprived of sugar to such an extent that my nails are at risk of being bitten again after 2 months of growing them really nicely... BRB. Off to raid the cupboards....