An investigation into whether politicians violated gift and disclosure laws when they accepted free game tickets or trips from the Fiesta Bowl led a prosecutor to conclude Wednesday that a maze of state laws was so complex and contradictory that he cannot pursue charges.

Inconsistent rules, vague reporting mandates and a legal requirement that prosecutors prove a defendant "knowingly" violated the law were major factors in his decision, Maricopa County Attorney Bill Montgomery said. In the end, there was not enough evidence to press charges against any of the 31 elected officials and three lobbyists who were investigated.

Montgomery said that for a successful prosecution, his office would have to prove that the officials and lobbyists knew when they filed required disclosure statements that "it was incomplete or false."