I have learnt that past participle phrase can be used non-restrictively, set off by commas, as in 1 and 2, but cannot only present participle phrase be used non-restrictively? If context is clear as in 3, isn't it a sure thing that "threatening people on the streets" modifies "the criminals"?
I will go through the tunnel, located across the street.
Pharmacists utilize a sophisticated computer system, designed to create more streamed lined workflow.
The cctv captured the criminals, threatening people on the street.
The cctv captured the criminals threatening people on the street.
So my questions are
Q1) Like in 1 and 2, can past participle phrase be used non-restrictively? As far as I know, past participle phrase at least can.
Q2) Like in 3, if context is clear enough for people to see "threatening people on the streets" as modifying the criminals, is it grammatically possible to use present participle phrase non-restrictively with commas in order to express the meaning that all the criminals captured on the cctv threatened people on the street? If not, could you give any reason why?
Q3) Is there a difference in meaning between 3 and 4? I think there is, To me, 4 sounds like not all of the criminals, but some of them threatened people on the street, and 3 sounds like all the criminals threatened people because of the comma. This is the main reason why I think of this question as important and am asking on and on.
Q4) Haven't you ever seen any sentences where present participle phrase is used non-restrictively as in 3?
Q5) When is it possible to use present participle phrase non-restrictively? Is it possible only in this case when the phrase can be seen only modifying the subject as in "Students, planning to study nursing, must first meet with the dean" ?
(I'm asking about present participle phrase that is set off by commas and is modifying not the subject, but the its preceding noun, as in example 3)
The point is that I want to know whether it's impossible to use non-restrictively present participle phrase to modify its preceding noun, not the subject in a sentence and if possible, when it's possible or not.