One or two were found not guilty, notably the widow Stella Alfonsi, whose husband's 1938 death by poison brought the case to light, and who was successfully defended by the lawyer Raymond Pace Alexander.
Herman was an expert counterfeiter and arsonist, with contacts in the criminal world, while Paul ran an insurance scam business from the back of his tailor's shop and aspired to a paid consultancy in 'la fattura', a magic believed in and resorted to by many in South Philadelphia's Italian community.
Meanwhile, Herman tried to steer clear of repeated attempts by the authorities to bring him to justice for insurance fraud, arson and currency counterfeiting.
As the Depression deepened, the Petrillos headed an informal gang, now including Morris Bolber and other self-styled 'fattuchierie' (wise women, witches) such as Maria Carina Favato, Josephine Sedita and Rose Carina, who offered superstitious, unhappily married, murderous or merely gullible women incantations, powders and potions to adjust their lives.
These 'love potions' usually contained arsenic, or antimony, and they were invariably accompanied by excessive insurance policies on the victims, often made out in favour of gang members rather than the supposed 'poison widow' beneficiaries.
The gang embraced insurance agents and made highly successful use of the period's widespread cheap insurance policies, often taken out without medical examination (not required for policies under $500) or the knowledge of the principal concerned, who would subsequently meet an agonising death by arsenic, engineered by the spouse; possibly with intent, possibly in superstitious ignorance of their actions.
Petrillo had offered to provide him with a large sum of money in both legal tender and counterfeit, if Meyer would perform the hit on Alfonsi.
He had been unaware of the policy, signing some documents with a cross while others bearing Alfonsi's signature were ineptly forged by Herman Petrillo.
Most importantly, each case involved a fresh life insurance policy with a double indemnity clause and a nearly direct lead to one of the Petrillo cousins, and each cause of death was listed as some sort of violent accident.