Part of the fun of watching detective shows is trying to figure out what happened based upon the clues that are revealed.

How much can you infer from these four images? 

This iron fence surrounds the outdoor patio at Ernesto's Restaurant in Sacramento. 

Patios must enclosed with a fence if the restaurant wants to serve alcoholic beverages to diners seated there. I think this is a city ordinance.

These additions to the top of the fence are the mystery. They appear to be hanging, but they are also welded in place.

These are round. There are six of these along the fence.

These do not have a round attachment. There are only two of this type on the fence.