Based on an anecdote as told by my colleague Lee. So if you don’t like it you can blame him.

The party had finished at 5am.
  Having spent an hour in his pre-slumber ritual of surfing the internet porn sites, Ricky was suddenly disturbed mid-stroke by an eerie sound emanating from the communal hallway.
  Armed with one of Linda's sling backs; discovered under a pile of dirty Y-fronts during a spring clean, Ricky eased open his apartment door and crept silently yet deftly down the staircase.
  With fear imprinted upon his sallow features, sweat glistening on his furrowed brow and his heart beating out the theme music to Jaws, Ricky hung on his last breath of stale air and turned the corner of the half-landing.
  The sight that met his blurred vision sent a shudder down his yellow spine, for there, lying in front of the communal lavatory, was….
  Ricky managed just two words before he passed out: “Holy shit!”

  He had no idea how long he’d been out for, but when Ricky came to his nose was mere inches from the steaming log. He could see sweet corn and tuna chunks as well as the traces of a pizza base; possibly deep pan or Italian.
  Looking up, Ricky found himself surrounded by his concerned flatmates, the horror of the errant faeces written on their faces.
  “Where did it come from?” asked Susan, an undergraduate in Tribal Dance Rhythms and Physics.
  “Who does it belong to?” questioned John; who was reading ancient Babylonian Birthing Rituals at the University of West Ham.
  “Eeuuw!” squealed Cindy, a loose sort who had decided to spend the night with Eddie; who was studying Freestyle Gynaecology with the Open University.
  Ricky looked into their eyes - not around their eyes but into their eyes. Had the stool been deposited by one of his flatulent flatmates? Could it be that one of the foreign exchange students was fluent in effluence? Did the pat belong to Pat?
  Realising that he was out of his depth - yet adamant that the crime be solved and the bowel bandit apprehended - Ricky picked up the telephone and dialled 999.

  Uniformed police were the first to arrive; twelve squad cars with flashing lights, blaring sirens and screeching tyres. They cordoned off the area with luminous yellow tape (demarcation of the defecation) and then drew a chalk line around the turd.
  Then CID arrived. They questioned all off the students at length using well-honed interviewing techniques such as; good cop, bad cop; doctors and nurses; and postman’s knock. But the students’ buttocks remained clenched; no one was talking.
  And then a team from forensics arrived on the scene. They took photographs and dusted for sphincter prints. The students were clean.
  Finally, Chief Inspector Spectre turned up to lead the investigation. He called on neighbouring houses and asked that the occupants supply excreta samples of varying shapes and sizes to be used in an identity parade.
  However, when asked to pick out the criminal crap from a line of a dozen dumps, Ricky was unsuccessful, and so the shit parade was dispensed with.

  After many long months of painstaking enquiries and several rounds of golf, the case of the wayward log was finally closed without an arrest.
 
  It was 11:35am on a Tuesday morning and Ricky was late for his 9:30 lecture on Ant Farming. Dashing across the communal hallway, he swooped to collect the day’s junk mail and slipped head-over-tit into a warm, yellowish-green puddle.
  “Now that’s just taking the piss!” exclaimed Ricky and dialled 999.