To put what appears to be a harmless object somewhere so it can explode and cause harm to anyone who touches it: The shooter at the theater in Aurora, Colorado, on July 20, 2012, had booby trapped his apartment and it took at least two days before the police could neutralize the explosives so they could safely enter the place to gather evidence.

• James Holmes, the Aurora, Colorado shooter, who reportedly opened fire at a Batman movie premiere, admitted to police that he had booby trapped his apartment with explosives.
• When police searched Holmes apartment, they discovered that it had been booby trapped and so they evacuated not only the building where his apartment was, but also the surrounding buildings.

The trapping of light inside a semiconductor material by refracting and reflecting the light at critical angles; trapped light will travel further in the material, greatly increasing the probability of absorption and hence of producing charge carriers.