“What’s the difference between a lawyer and a prostitute?” (lawyer joke)

Lawyers are often compared to prostitutes, and there’s a joke about it:
 
Q: What’s the difference between a lawyer and a prostitute?
A; The prostitute stops screwing you after you’re dead.
 
The joke has been cited in print since at least 1993.
 
   
Google Books
Lawyers from Hell Joke Book
By Ellie Grossman
New York, NY: Signet: New American Library
1993
Pg. 52:
What’s the difference between a lawyer and a prostitute? A prostitute stops screwing you after you’re dead!
   
Google Groups: alt.tasteless.jokes
various jokes
.(JavaScript must be enabled to view this email address)
6/22/93
Robert J Nunez (.(JavaScript must be enabled to view this email address)) wrote:
[...]
: What’s the difference between a lawyer and a whore?
: The lawyer charges more to screw you.
Actually, it’s:
 
What’s the difference between a lawyer and a whore?
The whore stops fucking you when you’re dead.
 
Google Groups: rec.humor
Canonical List Of Lawyer Humor 1/2
Tis The Season
12/16/93
(...)
What’s the difference between a hooker and a lawyer?
A hooker will stop fucking you when you’re dead.
   
1 September 1994, Washington (DC) Post, “Cybersurfing: Lawyers Subject To Writs of Wit’ by Howard Kurtz, pg. D7, col. 1:
“What’s the difference between a lawyer and a hooker? A hooker will stop when you’re dead.”
 
Google Books
Lawyers and Other Reptiles II:
The Appeal
By Jess M. Brallier
Chicago, IL: Contemporary Books
1996
Pg. 16:
QUESTION: What’s the difference between a lawyer and a hooker?
ANSWER: A hooker doesn’t keep screwing you after you’re dead.
   
IMDb (The Internet Movie Database)
The Rainmaker (1997)
Quotes
Rudy Baylor: What’s the difference between a lawyer and a hooker? A hooker’ll stop screwing you when you’re dead.
   
Google Books
The Complete Idiot’s Guide to Writing Erotic Romance
By Alison Kent
New York, NY: Alpha Books
2006
Pg. 169:
“What’s the difference between a lawyer and a prostitute?”
 
“A prostitute won’t screw you when you’re dead.”
   
Twitter
Bob Kostic
‏@causticbob
Q: What’s the difference between a lawyer and a prostitute?
A: A prostitute will stop screwing you when you’re dead.
3:08 PM - 7 Nov 2015