Possible theories on a mystery

In 2005 I was a witness to something very strange, at the time I lived in a district in Glasgow named Toryglen, I had decided in the middle of the night to go buy tobacco from the local supermarket, I walked down Prospecthill Road and noticed there was a strange smell in the air like something electrical burning and a faint hint of smoke in the air but more like a mist effect, I noticed there was a police car in the middle of the road and there was a section of the road cordoned off, as I got nearer I noticed a couple of policemen walking around in the bushes with torches obviously searching for something, I approached one of them and asked what was going on and one replied "that is what we are trying to find out" at this I noticed the part of the road cordoned off with police tape, some sort of camera was on a tripod and from the camera there was a blue light like a laser pointing towards the middle section of the part cordoned off, it was aimed at what appeared to be a small amount of a kind of debris, silvery green in colour, as I peered at it I noticed an old woman watching too, the only other witness to the episode. Foolishly I moved on down the road to the supermarket thinking that there would still be something going on when I returned to the spot, 6 mins in the supermarket and I was off back up the road, lo and behold the road was empty, not a sign of what had occurred only 5 mins previous

I posted this before and got ignored so thought I'd post it again as I wouldn't mind some theories on what it was all about

The boring answer would be that there had been a road traffic accident or a Police pursuit. If it was a pursuit, they might have arrested somebody and been looking to see if anything had been thrown from the vehicle they had been driving. Weapon or drugs possibly? Debris on the road supports the notion of a vehicle intervention. Toryglen can be a bit lively at night, I'd guess it's a normal 'Police dealing with a possible crime scene' scenario...

I must admit, I'd never heard of this before and I stay within a few miles. Could it have been a gas canister or something, or just the smell coming from Hampden