In March 1997, weeks after hiring defense attorney Valukus, and days after learning from the "Chicago Sun-Times" of their investigation into Burke's law firm and clients, Burke invoked a rarely used motion to amend the proceedings of the city council to change to abstentions four "yes" votes regarding airport facility leases for Midway and American airlines, two of Burke's seven airline clients. Burke blamed the recording of his "aye" votes on the late Alderman Thomas Cullerton, who chaired the City Council Committee on Aviation, which reviews airport leases. Cullerton had died in February 1993, three months before Burke cast one of the votes he changed. At the July 2, 1997 City Council meeting, Burke changed to abstention a June 4, 1997 vote in favor of a property-tax break for another client, Heinemann's Inc., a baked goods company in Burke's 14th ward. Between 1993 and 1997, Burke put through six journal corrections on his votes, some dating back seven years, and accounting for more than half the corrections from all aldermen during that period. In 2004, Burke changed the record of a vote in support of a zoning change favorable to another of his clients, Centrum Properties.