The scientific method isn't just for scientists. Detectives think it's pretty handy, too. The scientific method gives detectives a way to collect and think about evidence to solve a crime as quickly as possible. After all, nobody likes an axe murderer on the loose.

When a detective first arrives on the scene of a crime, there is dramatic music playing. Oops, we were thinking of our favorite CSI series. Let's try again. When a detective first arrives on the scene of a crime, they start looking for evidence. Anything and everything could be evidence.

A favorite form of evidence is DNA. Usually detectives look for DNA in the form of blood, but since it's found in all cells of the human body, hair, tissue, or other bodily fluids can be used as DNA evidence. DNA is unique to pretty much every person (hi there, twins!), so finding a sample of DNA can help us identify who was at a crime scene pretty accurately.

Next up on the popularity list is fingerprints. We've all got a unique set of fingerprints attached to the ends of our digits, and whenever we touch something, particularly a smooth surface like metal or glass, the oils from our fingers get deposited and leave behind a print. Detectives can use a special powder to collect these prints and match them up against the fingerprints they have in a database to see if they can determine who was at a crime scene. Obviously, this matching system only works if the culprit is in the database, but it's a good start.

If there was a gun involved, detectives may get some help from a ballistics expert. These experts will look at evidence the bullet left behind to determine what kind of gun it came from, the angle of the shot, how tall the shooter was, what hand they shot the gun with, and so on.

Then there's other evidence. Detectives may look for footprints or fibers from fabrics. They may look at the appearance of a room if there was a struggle, or look for evidence that an intruder forced their way in. While detectives and scientists are both focused on finding evidence, that evidence isn't always so obvious to the detectives.

Just like scientists have to collect their evidence carefully to avoid error, detectives have to collect crime scene evidence carefully too. They can't just go picking up stuff willy nilly lest they smudge a fingerprint or destroy a hair. Eventually this evidence is going to be used to argue a hypothesis about what happened, so it's gotta be the good stuff.

When the bad guy gets caught, then it's up to the lawyers to use all the evidence the detectives gathered to show whodunit. Sounds a little like what scientists do when they use evidence to argue that their hypothesis was correct, eh? Except when a scientist's hypothesis is wrong, no one ends up in jail (usually). Scientists also get to test out their hypothesis with an experiment, which provides direct evidence to support or refute their ideas. Detectives and lawyers test their hypothesis in a courtroom, where there are so many more variables involved that can influence how a judge or jury rules in a case.

Unlike our favorite crime shows, there are some mysteries that just can't be solved. Seriously though, how long have they been trying to figure out who shot John F. Kennedy now? This happens in science, too. Sometimes there are just scientific mysteries that we don't have the evidence to solve. Yet.