During part of the month-long deadlock, Mackell received the 14 votes of the Wagner men for Temporary President,[4] but was eventually replaced with Joseph Zaretzki.
On August 1, 1972, Mackell announced that nine of his assistant D.A.s, among them his son-in-law James D. Robertson, were cited in a federal investigation for income tax evasion as having invested money in a Ponzi scheme.
[6] In September 1972, Maurice H. Nadjari was appointed as a special prosecutor to probe into corruption in the law enforcement and judicial system of New York City.
[7] On October 10, the defence of Joseph Ferdinando, the operator of the Ponzi scheme, asked the Appellate Division to remove Mackell from the case, because his assistants were involved in it.
[16] His trial began on January 14, 1974,[17] and ended on March 2 with his conviction for conspiracy, hindering prosecution and official misconduct.