Jennifer vanished sometime in the overnight hours.

Right now there is no trace.

Investigators say evidence lead them to believe that she's dead.

Stick my nose back on the trail. That's all I can do.

This is already gone.

Already gone.

Already.

All ready. All right.

Going postal is a slang phrase many of us have heard or even used before.

The phrase originated in the late 1980s and early 1990s after a series of high-profile workplace shootings committed by disgruntled postal service workers. One of the earliest and best known of these shootings happened in

Edmond, Oklahoma in August of 1986. When 44-year-old postal worker Patrick Sherrill opened fire on his coworkers, killing 14 and injuring six others, before turning the weapon on himself.

Another of these horrific workplace shootings happened in the Detroit area in 1991.

Come with me to an overcast day in November, 1991, when 30-year-old Thomas McElvane opened fire at the post office in Royal son of a Marine veteran, his mother left when he was a young child, leaving Thomas and his two siblings to be

raised by a single father. Home was a modest brick bungalow, and Thomas grew up wanting to

emulate his father's toughness. Friends recalled that young McLevane was interested in karate

and martial arts from a young age,

often practicing his moves in the garage. After graduating from high school, Thomas followed

in his father's footsteps, enlisting in the U.S. Marine Corps. He served in Okinawa, Japan,

and at the 29 Palms Base in California.

Marines who served with him described him as both intense and volatile.

One peer recalled an incident where McLevane drove a tank over someone's car following an argument.

This incident led to him being discharged from the Marines.

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