Once in court, Beck's luck went from bad to worse. Despite the man who swindled the woman sounding less and less like Beck, the jury decided nonetheless that he was not only guilty, but that he'd been seducing ladies and relieving them of their jewelry multiple times since 1877, under the woefully unimaginative fake name "John Smith." For that guy's crimes, Beck was thrown in the slammer for five freaking years.

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A 19th century British slammer, no less.

Beck finally caught a break when it was found that "John Smith" was circumcised, while Beck was not. While we don't want to imagine how he proved this in a court of law, he was nevertheless off the hook. At least until three years later, when another woman accused him of theft, and he was again arrested and charged with another string of jewelry robberies -- "Smith" was still out there doing crime, still looked just like Beck, and the court system hadn't learned a goddamned thing from the previous incident. Beck was found guilty again and served another five years or so in the big house.

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"Mmm-hmm. Mistaken identity. Miscarriage of justice. Right. Can we wrap this up?"

His luck only turned around when the real John Smith -- who was actually an Austrian doctor named Wilhelm Meyer -- committed another robbery while Beck was in prison. Though they probably tried their best to prove Beck did it with telekinesis, they eventually nailed Meyer for the crimes, discovering that the mistaken identity simply came about from both of them looking like the most British man in history. Beck was awarded a full pardon by the king and given a truckload of money to boot.

Well, for a while they used something called the "Bertillion method," which was basically a whole bunch of measurements they took of the size and shape of different parts of your body and face. As well as being an unflattering additional humiliation if you're a fatty, it served as a pretty reliable system -- that was until 1903, when these two guys came along:

ScienceDirect
Jeez, way to ruin the Bertillion method for the rest of us, guys.

They're not the same man -- the one in the left mugshot is who, after being arrested, was asked if he'd ever been in trouble with the law before. He answered no, but an examination of his measurements told a different story. And he wound up being charged more harshly for lying, much to his confusion. Where West caught a break that the guy in the above example didn't, was that the criminal who matched West's measurements was already incarcerated ... in the same prison. That's the guy in the second mugshot, whose name was -- get this -- also William West (though he went by "William" instead of "Will").

After a thorough examination to make sure one of them wasn't a liquid metal terminator or maybe The Thing, authorities were forced to conclude that this was just a one-in-a-billion coincidence. This caused a new problem for prison officials, who had trouble telling the two Wests apart, which could have been disastrous for one of them: William was serving a life sentence for murder, while Will was in for a much lesser charge.

Jupiterimages/Photos.com
"OK, one of you has to wear these. Don't worry, your fellow inmates should appreciate a little levity!"

Thankfully, the prison warden, Major Robert McClaughry, started to hear word about a newfangled method of identification that used fingerprints instead of facial measurements. After switching over to the new system, the prison was finally able to tell the difference between West and West, and the example served as proof that the fingerprinting method was far superior. Not that there isn't still confusion, since, for example ...

For instance, in Germany, police working on a $6.5 million gold and jewelry heist found traces of DNA on a pair of discarded rubber gloves. Unfortunately for them, the DNA was a match for two identical twins named Hassan and Abbas. They both had their DNA in the database, but because their DNA is 99.99 percent the same, it was impossible to tell whose DNA was on the glove. With the twins keeping their mouths shut and quietly high-fiving each other, the cops had to let them go.

And in Arizona, either Orlando Nembhard or his twin brother Brandon killed someone outside a nightclub. Both were at the crime scene, but because they're identical twins, witnesses couldn't tell which one pulled the trigger. Cops were forced to drop the charges, at least until new evidence is found.

Ievgen Chepil/Photos.com
Go Team Murder!

But if you're an identical twin, don't start planning your crime spree just yet. It turns out there is one foolproof way to tell you guys apart, even if you were smart enough not to leave fingerprints. Experiments done by police in the Czech Republic showed dogs could differentiate the scents of identical twins 100 percent of the time. So all we need, we guess, is more dogs stationed around twin-crime hotspots. At the very least, the entire plot of The Parent Trap could have been avoided.

But then again, even if you don't have a twin, DNA can still wrongly nail you for a crime ...

After 20 days in jail, a second, more exhaustive DNA test showed that he was innocent. The problem is that DNA tests, contrary to what you might think, don't match an entire DNA strand up with one in the database (because DNA is mindbogglingly complicated). Instead, they just look for a set number of matches, or "loci." In the U.S. and U.K., 13 loci are considered a match. In other countries, the number is 10. But, because of incompatibilities in the way different police departments do the test, the European-wide database that fingered Hamkin only looks at 6. With those odds, you might wind up falsely accusing a gorilla.

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Actually, you're probably safe accusing most gorillas of murder.

The FBI claims that the U.S. standard of 13 loci gives 1 in 113 billion odds of a false match. But before you stop being paranoid, you should listen to Arizona state crime lab analyst Kathryn Troyer. While doing a search, she came across two felons with very similar profiles. Normally one would assume the felons were close relatives. But they were of different races, so that was unlikely. This led her to see how many other close matches there might be, and terrifyingly, she found dozens.

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"I don't want to turn this into a whole racial thing, but I really don't think I have the same DNA as you, Jerry."

By the way, fingerprint matching works similarly: Entire prints aren't matched; rather, a certain small number of similar points constitutes a "match." How often does that lead to false positives? No one knows for sure, but some experts think it might be 0.8 percent of all of them -- which would be 1,900 people each year.

But even when there is an exact DNA match, you can still wind up with cases like this next one ...

After some careful detective work to figure out how this guy was phantom-molesting people from his prison cell, they finally found the answer -- he'd previously received a bone marrow transplant from his brother, and the brother had committed the crime. The marrow transplant literally meant that his brother's DNA was floating around in his blood.

Of course, blood testing isn't the only way to match your DNA to a crime scene, and it's been noted that this whole mess would never have happened if they'd used the more common method of a mouth swab. But then, scientists have also discovered that, after you kiss someone, their DNA actually winds up in your mouth and hangs around in there, so keep that in mind before making out with any potential ax murderers.

Dmitriy Tereschenko/Photos.com
We don't judge. Just brush your teeth afterward.

Luckily, donating your blood marrow in an attempt to get away with a crime is probably too painful and complex a scheme for villains to attempt outside of a comic book.

Evan V. Symon is a Moderator in the Cracked Workshop. When he isn't being tried for a crime a one-armed man did, he can be found on Facebook and be sure to bookshelf and vote for his new book The End of the Line.

Related Reading: There's no better example of "mistaken identity" than being confused for a god- and this article is full of people who found themselves in that situation. Of course, the most common cases of mistaken identity occur in music. If you think Bob Marley wrote "Don't Worry, Be Happy" then you're as wrong as his dreadlocks were lice-ridden. If you're up for something more sinister, we have stories of intentional identity theft too.