Crime scene investigator says murderers all make one main mistake when committing a crime

Thanks to the advancements of modern technology it's now nearly impossible to commit the perfect crime.

Scientific advancements has allowed police investigators the ability to collect copious amounts of evidence from a crime scene and capture criminals' every move on CCTV.

However it turns out there's still one mistake the majority of murderers make when the attacking a victim - and it's way more obvious than you'd think.

Sharing her experiences from working on some of the country's most grisly cases - including the London 7/7 bombings - forensic scientist Jo Millington has revealed exactly what these mistakes are and why you can never fully clean a up a crime scene.

Take a look:

"We've got technology up the wazoo to detect crime, to understand what people have done [and] to detect trace amounts of evidence," Millington told LADbible.

"They [perpetrators] go to quite extreme efforts sometimes to get rid of the evidence."

However she went on to explain that it's 'impossible' to completely cover your tracks after committing a crime as 'every contact leaves a trace'.

When it comes to the mistakes criminals often make, you're probably thinking it's something along the lines of a stray strand of hair or the tiniest outline of a footprint, right?

Well it turns out that criminals can be just as forgetful as the rest of us, with several perpetrators being caught out by something as obvious as fingerprints.

Crime scene investigator Jo Millington speaks to LADBible. (LADBible TV)

"They forget that they're leaving traces of themselves on every surface that they touch," she explained.

"We've known about fingerprints for centuries and yet it's probably one of the main ways in which people are identified," Millington revealed.

So nothing at all like the gloved criminals in your favourite action movies or police procedural shows...

"You kind of think to yourself, 'how did you forget that you leave fingerprints?'"

Millington went on to share one particular case where she was able to identify a murderer after he chose to leave behind a message which he'd hand-written in the victim's blood.

Never underestimate forensic science. (William Whitehurst/Getty Stock Image)

"The perpetrator had taken the blood of his victim and he'd written a really horrible word on the wall and then done an exclamation point," she said, adding that the point contained his fingerprint 'in the blood of the victim'.

"You kind of think to yourself 'what an idiot'," she added. "I mean, seriously, did you not think that was going to lead to your detection?

"Don't underestimate forensic science."