drop a dime on and rat out

[Roger Shuy]

In a case I've been working on the writer of a threat message uses the
expressions, "I don't want to drop a dime on him" and "I don't want to rat
him out," both of which mean that the writer doesn't want to expose or
fink on someone else. I haven't been able to find any published resources
on these expressions, especially about what occupation or group might most
commonly use them But from my years of experience dealing with criminal
defense attorneys and prosecutors (as well as the suspects involved), I
recall them coming up in conversation regularly, leading me to suspect
that they are common to law enfocement, law breaking, and the
courtroom. I've informally checked with attorneys and FBI agents and they
agree. I was rather content with this notion until I read Anna Quindlen's
column in Newsweek on Jan 17, where she uses them both. But I know her
husband and believe he might have influenced her, since he is a New Jersey
criminal defense lawyer. So I'm still of the opinion that its domain is
the one identified above. But I'm not totally sure of this. I wonder if
other occupations or areas of life have producers of these
expressions. Any ideas? Of missed resources?
Roger