Doesn’t the Rabbi or any of his congregation have a phone or a camera?
Are there no security cameras on that street?
I recall a similar story in Iowa about a Jewish school being shot up. It turned out to be a single BB hitting a window, very likely fired by some kid who did not intend to hit it.
http://gunwatch.blogspot.com.au/2017/03/fake-bullet-hole-in-synagagoge-in.html
So much of this is in the mind of the person who claims to be intimidated.
>>Are there no security cameras on that street?
The smallest of our local synagogues definitely has a full suite of cameras. We got a call to check an odd happening there while I was on a police ride-along.