What's that on the road in Cops when Buster first meets Joe?

[Robert Moulton]

What is that all over the road in the shots in Cops in where Buster first meets Joe and ends up with his wallet? If you look at the ground you can see foot prints all over it, in what seems to me to be oil. Now I know that oil was put on the road if you needed something slippery for a shot but I don't see any need for that here. So what gives? Was there maybe some business shot that required the oil but did not make the final cut? Hard to believe it was a mess on the ground that was just there.