PHOENIX - Retired Phoenix police sergeant Paul Penzone announced Wednesday he is running against Maricopa County Sheriff Joe Arpaio for a second time, after giving Arpaio the toughest re-election race of his career in 2012.

Penzone told 12 News in an exclusive interview that while controversy surrounding MCSO had died down in recent years, it was time for the 83-year-old, six-term sheriff to go.

"If you lose touch with what's going on in your organization, then you've overstayed your welcome," said Penzone, who's running again as a Democrat. "I think it's been more about keeping his job than doing his job."

Watch more of our interview, in which Penzone discusses:
Losing touch
Officer-involved shootings
His life

"There comes a time when you're no longer managing an organization to the level that is deserved, not only by your employees, but by the community."

Arpaio barely earned more than 50 percent of the vote in the 2012 general election. Penzone, who was running for office for the first time, got 45 percent. Independent candidate Mike Stauffer took 5 percent.

Penzone was outspent more than 8-to-1 by Arpaio. The sheriff enters the 2016 race with $3.2 million in cash on hand as of January

RELATED: Candidate Joe Rodriguez explains trouble as prison guard

Hanging over the 2012 race was the federal government's May lawsuit against Arpaio for alleged racial profiling of Latino drivers. A federal judge in a separate case ruled in 2013 that the sheriff had violated the constitutional rights of Latinos.

Hanging over the 2016 race is the prospect of Arpaio being referred for prosecution on criminal contempt charges, for ignoring the judge's orders in that racial profiling case. A decision could come any day.

Penzone labeled Arpaio's conduct in that contempt case as "unforgivable."

On other topics, Penzone said:

Immigration enforcement: Penzone noted he created a Spanish-langauge version of the Police Department's "Silent Witness" programs, so witnesses of crime could come forward. He says it's up to the federal government to enforce immigration laws, and he wouldn't step on that responsibility. Penzone said Arpaio was pursuing "something for the sake of creating an issue. It's another example of why it's time to change the leadership there."

Black Lives Matter: "If we see and identify that there's a trend (in shootings) .. that indicates we're more aggressive in some communities than others, that can't be tolerated," Penzone said.

What he learned in '12: "I am going to spend more time with those who don't know me, that maybe are already set with their opinion, but just by having the chance to talk with them, if I can earn their respect and possibly earn their vote and turn what is really about three points (half the vote margin between him and Arpaio)." In other words, more outreach to Republican Arpaio voters

The 49-year-old Penzone ran the Phoenix Police Department's "Silent Witness" program for many years. He also served in the drug-enforcement unit and other capacities during his 21-year career.

Penzone will face former Arizona prison guard and first-time candidate Joe Rodriguez, who has the backing of the Maricopa County Democratic Party, in the August primary.

Sheriff Arpaio's campaign issued this statement in response to Penzone:

The voters of Maricopa County rejected Paul Penzone once before and they’ll do it again. Right out of the gate, Penzone has chosen to level petty, personal attacks against Sheriff Joe Arpaio. This is not what voters expect out of a campaign for the top law enforcement position in the county. In short, Paul Penzone lacks the character and experience necessary to be sheriff.

Disclosure: Paul Penzone worked as a corporate security consultant for the corporate parent of 12 News, and has provided on-air analysis for 12 News on public-safety issues.