Jacques Snicket, along with his siblings, is a member of V.F.D.. A tattoo of an eye is on his ankle, and because of this, and his one eyebrow, he was mistaken for Count Olaf in The Vile Village. He has two younger siblings, Lemony Snicket and Kit Snicket. He was murdered in jail as he was about to be burned at the stake by Count Olaf (disguised as Detective Dupin), who intended to frame Violet, Klaus, and Sunny Baudelaire.
In Lemony Snicket: The Unauthorized Autobiography, it was revealed that Jacques is a good friend of Jerome Squalor and that Jerome follows his advice. It was because of Jacques that Jerome bought the penthouse apartment in 667 Dark Avenue, the purpose of this possibly to direct members of the secret organization V.F.D. to safe places before the schism. Jacques did not want Jerome Squalor to marry Esmé, and sent a letter warning Jerome, but the letter was intercepted, possibly by the Hook-Handed Man who was disguised as a doorman. It was also revealed that Jacques disguises himself as a detective and is possibly the man who investigated the murder of Dr. Orwell, though this article was not published in the Daily Punctilio.
In The Vile Village, Jacques immediately recognized the Baudelaires, and tried to tell them about their parents. He was a known member of V.F.D. and was on the fire fighting side. But unfortunately, Esmé Squalor, disguised as a police officer, Officer Luciana, stopped him from any further explanations.
In The Slippery Slope, the Baudelaires found a message that was thought to be for Jacques, but decided (with the later confirmation of Captain Widdershins) that no one would send a message to Jacques, since he was dead. Captain Widdershins also mentioned that Jacques was formerly part of his crew on the Queequeg.
In The Penultimate Peril the Baudelaires learned that J.S., the mysterious receiver of the message in The Slippery Slope, was possibly both Justice Strauss, following the orphans since Mr. Poe had taken away and Jerome Squalor, following the footsteps of his deceased friend.