PHOENIX — The full-throated bravado that made Sheriff Joe Arpaio a household name in debates over illegal immigration and the treatment of jail inmates was missing as he started his last news conference in a law enforcement career that spanned a half-century.

After being booted from office by voters, the 84-year-old Arpaio looked tired and dispirited as he defended his investigation of President Obama’s birth certificate — a debunked controversy that critics say Arpaio exploited to raise funds from his supporters.

The sheriff mispronounced several words as he attacked the birth record of the president he blames for his political demise.

The media-savvy lawman ended the news conference by uncharacteristically declining to mix it up with reporters about the credibility of the five-year Obama investigation by his volunteer posse.

He told his 75 supporters in the room that the investigation wasn’t about whether Obama was born in the United States and instead focused on a claim that the birth certificate was fraudulent.

The investigation was another questionable tactic in Arpaio’s 24-year tenure as the sheriff of metro Phoenix that ended Sunday and was also marked by traffic patrols and business raids that targeted immigrants.