From My Perfect Automobile:
In many states the highway patrol carries two gallons of Coke in the trunk to remove blood from the highway after a car accident.
I doubt it's real. Does Coca-Cola work this way?
Mythbusters actually gave the blood cleaning a "Confirmed" in that episode (although said nothing about police carrying cola). And Snopes says that using Coca-Cola to clean comes from a fellow by the name of Joey Green. As Snopes says:
That you can cook and clean with Coke is relatively meaningless from a safety standpoint you can use a wide array of common household substances (including water) for the same purposes; that fact alone doesn't necessarily make them dangerous to ingest. Nearly all carbonated soft drinks contain carbonic acid, which is moderately useful for tasks such as removing stains and dissolving rust deposits (although plain soda water is much better for some of these purposes than Coca-Cola or other soft drinks, as it doesn't leave a sticky sugar residue behind).
As for the claim that police use Coca-Cola, I think that is just an extension of the "Coke is Bad" myth that Snopes took on. Keep in mind that it's not the job of police to clean up accident scenes. Instead, they investigate the scene, and it is left to other professionals to do the clean up (such as medical personnel, since in many cases blood could be used for either evidence in a criminal investigation, or that it is a biohazard)
Considering that there is basically no information on this subject I doubt it's real (This question is #4 in a Google search for "blood dissolves in coca cola").
You might want to take a look at this article: http://science.howstuffworks.com/crime-scene-clean-up1.htm
It explains some of the equipment, which I quoted some of below.
Personal protective gear - a non-porous, one-time-use suit, gloves, filtered respirators and chemical-spill boots Biohazard waste containers - 55-gallon heavy duty bags and sealed, hard-plastic containers Traditional cleaning supplies - Mops, buckets, spray bottles, sponges, brushes, etc.
Hard-core cleaning supplies - Can include: Ozone machine (to remove odors) Foggers (to thicken a cleaning chemical so it can get all the way into tight places like air ducts, usually for odor removal) Hospital-grade disinfectants (bleach, hydrogen peroxide) Industrial-strength deodorizers Enzyme solvent (to kill bacteria and viruses and liquify dried blood) No-touch cleaning system (to clean blood-coated surfaces from a safe distance -- includes heavy-duty sprayer, long scrubbing brush, wet vacuum) Putty knives (to scrape up brain matter, which dries into a cement-like consistency) Razor blades (to cut out portions of carpet) Shovels (in about two hours, large amounts of blood coagulate into a Jell-O-like goo that can be shoveled into bags) Truck-mounted steam-injection machine (to melt dried brain matter that cleaners can't remove with putty knives) Chemical treatment tank (to disinfect and store matter sucked up by vacuum systems) Carpentry/restoration tools - sledgehammers, saws, spackle, paint brushes Ladders Camera (to take before-and-after shots for insurance purposes) Van or truck for transporting all of this stuff (and hauling waste to disposal site after clean-up)
This question sheds some light: http://answers.yahoo.com/question/index?qid=20071023213703AAWWgoq saying that water with some alkaline detergent would work better.
It is also not usually the police's job to clean up, and the fire department will often have to do that work.