The Most Inaccurate Things in CSI TV Shows

Are you ready to have your favorite crime drama ruined?
Trevor English

Crime dramas are some of the most popular shows on television. From CSI to NCIS to Law & Order, crime and the way crimes are solved seems to have a certain way of catching our attention.

Some of the coolest things about these shows are the high-tech methods that they are using to track down the suspects. Things like real-time DNA analysis, enhancing photos, dusting for fingerprints, and much, much more of the cool stuff. Sadly, like all things Hollywood, a lot of these methods are more fiction than reality, at least in terms of how well they work. 

If you'd like to remain oblivious to how inaccurate crime TV shows are, then I'd stop reading now—otherwise, let's take a look at some of the biggest inaccuracies in these popular shows.

DNA testing & analysis

It seems like the agents in popular crime shows are able to grab any bit of DNA from anything, send it off to analysis, and have the results almost instantaneously. This usually isn't the case in real life.

DNA testing takes a long time, or rather, the entire process from collection to results takes a long time. Typical DNA testing on a sample can take anywhere from 24 to 72 hours, but that's the time it takes from when a sample is placed in the machine. Standard timeframes from collection to final analysis are usually in the realms of 10-14 days. What that ends up meaning is that DNA results are usually only used for evidence in court for a perpetrator already detained. If you were counting on DNA to give you probable cause to hold someone, well then, you'd probably end up having to release them before you got the results back. 

There's a new DNA test called RapidDNA that can take as little as 90-minutes. However, it's fairly new to the scene, and it isn't compatible with the FBI database, so it hasn't been rolled out heavily across the industry.

It's also notable to mention that the timeframes we mentioned above for DNA testing depend on the number of samples. Any given scene could have tens to hundreds of samples, extending the testing time for DNA out even further.

DNA testing also can be fairly inconclusive, even when you have an exact match.

Take, for example, a crime where a man was killed, and the primary suspects are his wife and friend. If you were to test that man's fingernails for DNA, you'd likely find the DNA of both suspects, or even if it was just one, due to the nature of the aforementioned relationships, it really wouldn't prove anything. Maybe the friend and the victim shook hands, it's likely, and it's equally likely that he held hands with his wife, transferring DNA in that instance too.

DNA, like all other crime scene evidence, has to be used as a small piece to the larger story that is any given crime scene. While DNA has been used to conclusively convict or overturn people's sentences, sometimes it can be thought of too concretely, resulting in a wrongful conviction.

Fingerprints are not easy to find

Most of us probably have some idea of how to lift a fingerprint off of an object, thanks to our favorite crime drama. Pull out some fine powder, like makeup, dust it overtop a surface and use clear tape to lift the print. Easy, right?

The ability to lift a fingerprint, or even find one, depends heavily upon the surfaces present in the crime scene. Weapons like guns can sometimes be hard to lift prints from due to their uneven surfaces distorting the fingerprint.


Even when there is a print that can be lifted from an object, actually matching that print to a matching person can be hard, even highly inaccurate. 

Think about the fingerprint sensor on your phone. If you have any liquid or oil or pretty much anything on your hand, you won't be able to use the sensor to open your phone up. The same is true for matching uplifted prints. Any imperfection in a print found at a crime scene can mean that the forensic specialist has to make some guesses when matching the print, and it may have to be examined manually, not in some fancy algorithm. Any errors in the lifted print can also lead to false matches, meaning wrongful convictions.

 The Most Inaccurate Things in CSI TV Shows

Finally, partial prints are very common, but they actually take less time to analyze, and often can't be used to find suspects. Partial prints mean fewer key features on a print to match up with a potential suspect or victim. In order for the authorities to be able to match up a print, they need a statistically significant number of matching features on a print, which is something that partial prints often can't provide.

Forensic analysts don't make bank

Most crime TV shows place their respective forensic analysts on a pedestal, practically equating the work they do to witchcraft. However, in reality, forensic analysts are paid fairly poorly compared to the officers they work with.

In the US, the pay for forensic analysts ranges from $32,760 and up to $84,000, with many many years of experience. Not a terrible income, but when you put it in perspective of the average detective salaries in the US being $83,320 to $135,530, it definitely pays to be on the sworn officer side of things.

Focusing in on actually being a sworn officer, that's the key difference between detectives and forensic analysts. Detectives are sworn into their roles, whereas forensic analysts are normally just people hired to do a job, like any other office job. Sworn officers will carry guns and can arrest people, whereas forensic analysts can't do any of that—in most cases.

This all, unfortunately, means that the TV show Dexter falls apart quite quickly, there's no easily explainable way he could've had all the money he did—unless he was pocketing all the evidence cash that came his way.

Paperwork, paperwork, paperwork

One thing that is always missing from crime dramas is just how much paperwork is involved in the process. Brooklyn 99 does a fairly good job at least hinting to how much paperwork officers do, but if you talk to any cop, most of their job is filling out endless forms and making sure the paperwork is up to date. In the world of crime, documentation is everything. Without proper documentation, evidence can easily be thrown out in court, or worse, suspects can be released.

So, at the end of the day, crime shows on TV are impressively good at capturing our attention, but most of the methods they use to catch criminals are overdramatized, and while based on reality, are mostly science fiction.

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