You've probably seen or read about this before in books or on TV; the grizzled old detective steps into the scene of the crime and sees the lighter/handgun/baseball bat left behind by the criminal. He gets to work, likely yelling at a couple members of the forensics team in the process, and starts to close in on the perpetrator.The detective is then promptly kicked off the case, possibly due to some trick by the villain, and the case is closed. Unable to shake the feeling that the crook got away he takes the evidence home, and with the power of super glue extracts a perfect fingerprint and catches the nefarious villain.
But how does it work? Well, super glue is made of cyanoacrylate, a substance that, when heated to a vapour, reacts with the oily residue left behind by the pores of the finger to create a clear image of a fingerprint on a piece of evidence, such as a gun. if the evidence is put in a heated airtight container with high humidity along with super glue the super glue will boil away into the immediate atmosphere and will eventually settle on the residue left behind by the finger. The reaction gives the residue a whitish appearance, making the fingerprint easy to see.