Acosta, a leftist who goes by 'Juanito,' delivered his resignation after foes threatened to seek prosecution on charges that his candidacy papers were falsified. Acosta this week gave reporters conflicting birthdates, first saying he was born in 1958, then 1960. His family background has also come under scrutiny. Clara Brugada, who fought Acosta for the job, threatened to file a criminal complaint. Mexico City Mayor Marcelo Ebrard will propose a possible replacement to local lawmakers. Acosta's resignation apparently ends the roller-coaster-like drama swirling since July over Iztapalapa, a working-class community with nearly 2 million residents. At that time, Acosta won election as delegado, a mayor-like post, as part of a deal in which he would hand over power to Brugada, who had been ruled off the ballot. The arrangement ran into trouble after Acosta won on July 5. He first flirted with keeping the job, but then agreed to take a leave of absence, clearing the way for Brugada to take over. Then, last week, as Acosta's two-month leave ended, he announced he would take over the job after all. He fired Brugada and her team, and she appealed to the Mexico City legislature to oust him. Lawmakers were studying the matter when Acosta resigned. 