In researching peter player ‘a robber who uses administers knockout drops to victims’ for the Historical Dictionary of American Slang, I came across an article that says the term peter player was named after a Peter Sawyer known for using knockout drops on victims.
If that’s true, then peter player may have been the original form, and its synonym peterman, as well as peter ‘a sedative; knockout drops,’ may be derived from it.
From the Sandusky (Ohio) Register, May 18, 1894, p.7, reprinting an article from the New York Sun:
It would be hard to find a lower class of criminals in this city than the cowardly frequenters of the Bowery, who nightly secure victims through the medium of what is known in police parlance as “knocker out.”…They are known to the police as “Peter players,” because the pioneer of the business in this country was old Peter Sawyer, as desperate a crook as ever got in the hands of the police in this city. […]
A form of administering “knocker out” which came in after Peter Sawyer’s snuff game went out was by a ring with an adjustable stone. The stone was worn inside the hand, the plain band of the ring belting the outside of the finger. A spring would move the stone to one side. Under the stone the crooks would conceal a morphine or opium pill, which they would drop into a glass of beer or whiskey.
Knocker-out is now a disused term, but at the time it meant someone or something which literally (such as a boxer, a peter player, or sedatives) or figuratively (such as a beautiful woman or someone very competent at a task) knocks someone out.
This claim that Peter Sawyer is the source of the term is also repeated in Asbury’s Gangs of New York, first published in 1927 (and very little like the movie supposedly based on it, by the way), as well as in Luc Santés Low Life (1991), but Santé probably got it from Asbury, who probably got his information, in turn, from the New York Sun or other newspapers. Asbury wrote (p. 181):
The late [eighteen-]sixties also saw the beginning of a reprehensible practice of using knock-out drops to deaden the senses of a victim while the thieves picked his pockets or appropriated his jewelry. Laudunum had occasionally been employed by the crimps of the old Fourth Ward water front to drug a sailor so he could be shanghaied without too much protest, but no effective use of drugs for the sole purpose of robbery was made in New York until a California crook, Peter Sawyer, appeared in 1866, and aroused such a furore in police and criminal circles that the former honored him by calling the practitioners of his art peter players. At first Sawyer used nothing more deleterious than snuff, which he dropped into his victim’s beer or whiskey, but later he and other peter players came to depend principally on hydrate of chloral. Occasionally they used morphine.
A crimp, according to Asbury, was someone who “operated boarding houses where sailors were robbed and murdered and from which they were shanghaied” (p. 48).
In his book, Sante adds the detail Sawyer came to New York City in the 1850s (p. 108).
I’ve found no other trace of Peter Sawyer, but I admit I haven’t looked very thoroughly. It’s one of those tasks I could spend weeks on for no result. I’m satisfied, for the moment, by the minor delight of antedating OED’s entry for peter by four years.