Man leaving the scene was recorded saying, 'I killed Jennifer"
Wore the device while mapping out an escape route for a contract killing
It's not the first time that modern tech has been used in these cases
Claims suspected infidelity is what caused her to snap
Police have charged the suspect with murder
The videos were up for 24 hours and shared on YouTube
Murderer takes his own life rather than face police
Steve Stephens is considered armed and dangerous