One day at work I was called into the front office. There was a man there, introduced to me as a police detective, who handed me a packet of photographs and asked if I recognized any of them. I immediately recognized that they were all shots I had taken. Amazed, I asked the detective how he had gotten them and how he had tracked them to me. I was surprised to learn that my camera had been stolen from my car earlier that week. The detective surmised that I must have left a door open. The thief had attempted to remove another camera from the car of someone who lived on the next street over. However, this time the car's owner saw what was happening, raced to his car and tackled the thief. During the ensuing struggle the thief dropped my camera to the ground. It was smashed. My neighbor managed to detain the thief until the police arrived. Later, on a whim, the detective had my film developed. One of the photos showed the entry sign to my workplace, complete with address. The rest was easy.

The point is that sometimes the police get lucky. Sometimes they have what is needed to put them in the position of being able to track down the owners of stolen items. Sometimes all that is needed is a good, solid clue.

I would most certainly advocate marking at least your most marketable items. It couldn't hurt and might even help.