Did the word shyster come from Shakespeare's Shylock?

According to Gerald L. Cohen, a student of the word, shyster is derived from the German term scheisser, meaning literally "one who defecates," from the verb scheissen, "to defecate," with the English suffix -ster, "one who does," substituted for the German suffix -er, meaning the same thing. Sheisser, which is chiefly a pejorative term, is the German equivalent of our English terms bastard and son of a bitch. Sheisser is generally thought to have been borrowed directly into English as the word shicer, which, among other things, is an Australian English term for an unproductive mine or claim, a sense that is also recorded for the word shyster.

http://www.thefreedictionary.com/shyster

shyster -- unscrupulous lawyer," 1843, U.S. slang, probably altered from Ger. Scheisser "incompetent worthless person," from Scheisse "shit," from O.H.G. skizzan "to defecate" (see shit).

http://www.etymonline.com/index.php?search=shyster&searchmode=none