If you're a fan of 'CSI,' please watch John Oliver's exposé on forensic science just in case you ever get called up for jury duty. Boning up on the flaws with forensic science could save someone's life. 

"Prosecutors often complain about a so-called 'CSI effect' where jurors expect to see forensic evidence in every case," Oliver noted on yesterday's episode of Last Week Tonight. "The problem is, not all forensic science is as reliable as we've been accustom to believe."

In fact, nearly half of the hundreds of exonerations that have taken place since 1989 have involved cases where forensic science was misapplied. In one case, a man named Santae Tribble was convicted of murder when hairs found at the crime scene were identified as his. But after serving 26 years in prison, Tribble was exonerated when DNA analysis found that none of the hairs belonged to him. And one was actually a dog hair.

So you could wind up spending a quarter of a century in jail thanks to a dachshund doppelgänger. 

And that's not the only incident where analyzing follicles has failed. From the 1970s to the 1990s, there were 268 convictions where hair analysis was submitted as evidence. Of those cases,  257 (or 96 percent) used flawed forensic testimony. And 9 of those defendants had been executed by the time the mistakes were revealed. So even though Tribble lost 26 years of his life, he is actually one of the luckier ones to go through this legal nightmare. Which is probably the bleakest bright side you can imagine.

And hair analysis isn't the only flawed form of forensic science. Bite marks, fingerprints and even blood samples can also lead to wrongful convictions because investigating crime scenes is rarely as straight-forward as what you see on TV. That's why Dr. Michael West, a bite-mark expert, has said that he no longer believes in the validity of his own field of forensic analysis.

Yet judges still allow bite marks as evidence because of legal precedents. Basically, since courts have allowed that material before, they're obligated to do so again. But you can help by educating yourself about the flaws in forensic science and sharing it with others so that society can become more knowledgable about science.

And to help, Oliver put together a special CSI clip highlighting fundamental flaws with forensic evidence. Check it out.