meaning - Allow, Allow Of, Allow For

I am confused about the usages of "allow", "allow for" and "allow of". Suppose police

is examining the evidence related to a bank robbery:

1. The evidence allows the possibility of an inside job.


2. The evidence allows for the possibility of an inside job.


3. The evidence allows of the possibility of an inside job.

I checked a number of dictionaries and google. It seems that the usages in my three sentences are understandable English. But what do native speakers on this forum think?