Pustule stared long and hard at the photograph. Then he went and got a magnifiying glass and peered closely. He gave a sigh of relief, tell-tale signs such as globules of chicken burger, slivers of pork scratchings and finally strands of the cat's pubic hair re-assured him that the dribble was his and that Alan was not incontinent after all.

Then Pustule's mobile rang. He answered the caller sharply,

"Pustule here, who's calling me this bloody time of night?

Oh,

I'll be down the station right away.

Alan I'm off down the station, to see the boss."

Pustule stormed into his bosses office, "This has got to be bloody urgent, I was about to slip into something comfortable"

The Boss replied,"I'll come to the point, Pustule you're off the case"

"I'm bloody what?"

"You're off the case"

"I don't understand"

"Pustule I'll say it slowly

you're

off

the

case"

"Yes but why?"

Because of your blatant Homophobia. 

By the way, Segeant Dribble has arrested the killer, Mrs Scrub has  made a full confession. The young lady pathologist noted that the substantial injuries suffered by the victim, (Mr Scrub) could only have been made with a scouring brush. They matched marks that Mrs Scrub had made on various surfaces in the loos. Dribble put one and one together, and it all fell into place

"Well bugger me" exclaimed a bewildered Pustule.

"Not while there's dogs about" commented Sergeant Dribble; who had silently entered the office.