Warning: If you are squeamish about blood, don't read this entry.
J'accuse!! Clue CSI: Cosplay investigates a crime scene!
Upon arrival on the scene, Detective Peacock immediately notes, marks, and samples a large collection of blood drops located by the door leading from the Garage to the Front Hall.
Forensics Expert Plum promptly notes that the even pattern of blood spatter indicates that the victim was standing, or at least stationary, at the time of dispersal.
Investigator Green knows why: Blood evidence on the knob indicates that someone as attempting to open the door.
Trying the door - carefully, as to not disturb the evidence - reveals a telling clue: the door knob only functions when turned counter-clockwise. A clockwise turn will not free the deadlatch from the strike plate. The obvious deduction is that the victim spent a few seconds here struggling with the doorknob. This explains the next progression of blood spatter, leading from the Garage-to-Front Hall door out the Garage overhead door to the Driveway. Forensics Expert White notes two telling things about this: First, the size and proximity of blood spatter indicates that during the time the victim struggled with the door, some blood had pooled, and dropped when the victim turned and continued running. Second, the spatter of the large blood drop, followed by several smaller drops in a line, confirm the direction of movement, Investigator Green deduced: the victim traveled from Garage to Driveway, and not the opposite direction.
Detective Mustard notes that during the time it took for the victim to open the front door from the Driveway to the Front Hall, two drops of blood fell on the threshold.
Meanwhile, Agent Scarlet has been working the crime scene backwards, and has found what appears to be both the exact location of the crime as well as the weapon: a sharp blade! The blood has only just begun to dry around the margins; this surely could not have occured more than half an hour ago.
They have the what, the where, the when, and the why is lies all about them: piles of cut sheets of plastic, some of it still on the bench beside the weapon. What evil motive is this?? And all that remains is... the who! Cautiously, the team follows the trail of blood inside, through the Front Hall and upstairs, noting that the victim did not drop any more blood along the way. Could they be in error? Did the victim truly not make it through the front door? No, a smudge of blood on the door at the top of the stairs indicates the sleuths are still on the right trail! Fanning out, it doesn't take long to find the next clue: the white porcelain sink in the nearest commode is stained with red smears. But where is the victim? Escaped? Or already dead and the body hidden? Hearing a noise, they turn as one, and see...
Both the victim and the perpetrator of the crime, caught red-handed! The stains on her shirt amply show why there were no blood drops on the stairs. She looks none the worse for wear, although a bit sheepish and maybe a little grey from slumping on the floor with her hand under the faucet to let the wooziness pass enough for her to climb another flight of stairs to where other witnesses were able to patch her up with some gauze and athletic tape.
Case closed!
...Frakking xacto knives.