At the time of Peter Weinberger’s abduction, there was a federal law in place that prevented the Federal Bureau of Investigation (FBI) from intervening in a kidnapping case for seven days, after which it was to be assumed that the victim had been taken across state lines, allowing for a federal investigation. So after a delay of a week, the FBI was only just then able to put their manpower into identifying who had snatched the month-old baby, the wellbeing of which was becoming more of a concern with each passing hour.
Agents combed millions of documents, per Newsday, in their search for a handwriting match for the ransom notes, which they knew was the key to identifying the kidnapper. They finally had a breakthrough on August 22, 1956, after which Angelo John LaMarca was arrested. Though he originally denied his involvement in the kidnapping, the evidence was damning, and LaMarca confessed. Two days later, investigators discovered the remains of Peter Weinberger at the site LaMarca said he had abandoned him. He had died of asphyxia, starvation, and exposure, with the Nassau County medical examiner suggesting that the newborn may have lived for up to a week after being abandoned.
Though LaMarca claimed insanity, he was found guilty of both the baby’s kidnapping and his killing. He was sentenced to death by the state of New York, and died in the electric chair at Sing Sing prison on August 7, 1958. The law preventing FBI involvement in kidnapping cases until seven days had passed was later amended to allow for them to begin such investigations after just 24 hours.
