PHOENIX -- Maricopa County Sheriff Joe Arpaio said his next crime suppression sweep on Wednesday will be a lot different from all the others.

But he stopped short on Saturday explaining how the latest crackdown will vary from the others. And he didn't announce which community he will target.

"I don't want to publicize it now and get all the politicians involved with all of their friends who are demonstrators," Arpaio said. "They always make it a political thing."

During past crime sweeps, sheriff's deputies typically canvass a chosen area, pulling over any driver breaking the law, even minor infractions. Those who are in the United States illegally are immediately arrested.

A vocal opponent of the tactic is Phoenix Mayor Phil Gordon.

"I believe the public would rather have officers going after felons than somebody pushing a cart across the street and didn't stop at the crosswalk," Gordon said.

Gordon said he a finds it bizarre that the sheriff announces his plans in advance.

"A crime suppression raid where you're targeting individuals by announcing you're coming. I don't understand the logic of that," Gordon said.

Arpaio said he publicizes his raids to encourage voluntary compliance.

"Maybe they will leave town, go back to the country they came from, and get out of town because they know the sheriff is coming," Arpaio said. "And that's great. If they leave, isn't that great? "So I want people to know we're doing this."

Since the crime sweeps began, about half of those arrested have been illegal immigrants, according to the Maricopa County Sheriff's Office.

New numbers from MCSO shows crime in Maricopa County has dropped 10 percent over the past year.

Arpaio said the numbers only pertain to those areas in the county that are unincorporated -- those communities that have no local police department and that are policed by the county.

The sheriff reports that violent crimes, including murder, rape, aggravated assault and armed robbery have declined by 10 percent when compared with the same time frame in 2007.

Arpaio said his deputies have cleared almost 8,000 warrants this year, most of which are felonies.

The sheriff credits his planned crime sweeps as one of the reasons the crime rate has declined. Since the sweeps began, the sheriff has arrested 270 people, half of which are illegal immigrants.

Gordon said he's reluctant to believe Arpaio's numbers.

"I don't think anybody should draw a conclusion on a verbal press release without the actual statistic," Gordon said.

Arpaio shot back. "When you look at the jail I run, 10,000 inmates, 2,000 out of the 10 are illegals, that's 20 percent in my jail," he said. "I have proof."