While sorting through some older pocket change, I discovered this unusual penny. Most obvious is the letter "L" stamped above the date. Closer examination reveals a shallow dimple drilled or punched on the back of Lincoln's head while the word God in our national motto has been partially obliterated. Assuming these were done by the same person at the same time, does anyone know if there is any significance or symbolism associated with the alterations? Thanks.

The dimple would seem to represent Lincoln being shot. There are some other dimples in the raised perimeter, but I have no idea what those might mean or the L stamping.

Looks like something that occurred after the coin left the mint

^^^ No doubt about it.

Robert Langdon could tell you what those symbols mean.

Put a pin in the dimple, and tap gently to see if the coin has been hollowed out.

Back in the day, microfiche was smuggled inside of hollow coins.

The Soviets were particularly good at machining out a hollow coin, and moving information inside it.