The federal abuse-of-power investigation into the controversial sheriff of Arizona’s Maricopa County, Joe Arpaio, has been closed, with prosecutors saying no charges will be filed.

Authorities were investigating Arpaio for his part in failed public corruption cases against officials who were odds with him. The sheriff brought cases against a judge and two county officials in 2009.

Federal authorities also said Friday that they have decided to not prosecute matters tied to alleged misuse of county credit cards by sheriff’s officials, alleged misspending of jail-enhancement funds and other matters.

“They did their investigation, they didn’t find enough probable cause and they didn’t bring an indictment,” Arpaio said at a hastily called news conference after returning from the Republican National Convention in Florida. “We don’t go around framing anybody. My people are not crooks.