Born Carl Menarik in 1889, Frederick Mors emmigrated to the United States from his native Austria in 1914 and soon found work at the German Old Fellows Home in the Bronx. Mors bordered on delusional, falsely claiming to be a legendary hunter and at the same time ruling the home with a heavy hand and forcing patients to refer to him as "doctor", though he was not and in fact wasn't even an important man there, holding down a fairly routine position.

Mors may have began killing very soon after he began working at the home, but nothing was suspected until January 1915. The clearly disturbed Mors was immediately suspected in the deaths of the elderly patient's deaths and under direct questioning admitted his guilt without hesitation. He had perfected a method of chloroform poisoning after having troubles with his first victim, who he had killed with arsenic.

Mors claimed he was only putting the old people out of their misery and making room in the crowded home. He was found criminally insane and placed in a mental hospital though he had murdered as many as seventeen people. Mors was to be deported back to Austria at one point but escaped the hospital first and was never heard from again.