4. Forensic Science cannot solve a crime
There are so many movies and tv series that show that crimes are solved by forensic science through the help of DNA strands as such. In real terms, DNA evidence is essential key to prove a crime and thus put someone behind the bars, but things are actually a bit more complicated. A crime scene may have the contamination of DNA from all around the scene coming from strangers passing the scene. So it is usually hard to solve a crime by forensic science through just DNA.