So if my sentence was in context, as a part of an article or story for instance, and it was clear that the the criminals were aided in "the past", do you think it would be correct?
I strongly favor the perfect form, but context might help.
David, would you mind telling us your opinion about a sentence like this one?:
- The criminal is suspected of being aided by other individuals in his last two robberies.
I personally prefer The criminal is suspected of having been aided ... or The criminal is suspected of relying on the aid of ..., but your view will prevail.