In a city dominated by diehard Democrats, the Republican candidate for Philadelphia district attorney faces daunting odds: Just 13 percent of the electorate shares his party affiliation.

On the campaign trail and in his advertising, Untermeyer pitches hard for crossover voters, using frustration with "revolving-door justice" as his rallying cry.

"Enough is enough," he repeats above the wail of a siren in TV ads peppered with squad cars, ambulances, a sheet-covered body, and flashing blue lights. "When I'm D.A.? Do the crime, you'll do the time."

Tough rhetoric. Grisly images. But where's the beef?

In a recent interview, the 58-year-old lawyer, real estate developer, and former prosecutor outlined his priorities. He wants to eliminate plea bargains for gun crimes. He proposes to reform the bail system. He would expand the D.A.'s asset-forfeiture and financial-crimes units to offset the recession's budgetary bite on the office, which has 300 lawyers and 250 support staff.

Property seized from criminals and fines levied against corporate wrongdoers could contribute millions annually to the current D.A.'s budget of about $22 million a year, he said.

The heart of Untermeyer's appeal is not fiscal, however. It's visceral.

"We have rampant gun violence," he says time and again at campaign stops. "We need zero tolerance for illegal handguns. Right now, 49 percent of people who go to gun court are put on probation" because the D.A. permits pleas to lesser offenses.

Untermeyer says he would offer two choices: plead guilty to a crime that results in prison, or go to trial.

He proposes changing the system in which a defendant generally posts 10 percent of the bail amount set by a judge and is responsible for all of the bail if he flees.

"That's an I.O.U." that in practice is never collected, said Untermeyer. "The system is insane. We might as well put up a sign that reads, 'Come to Philadelphia - for the restaurants, the theater, and to be a criminal.' "

The result is a system in which thousands of defendants have failed to appear in court and owe the city more than $1 billion, he said, citing recent news reports.

Untermeyer wants defendants to post full bail, with collateral if necessary.

To make the criminal justice system "more victim-focused," he said, he would assign assistant district attorneys to manage cases from start to finish. Currently several A.D.A.s might be assigned between the preliminary hearing and the trial.

If it sounds like Untermeyer's solutions would clog the courts and overcrowd the prisons, he has a ready answer: Use better technology to solve crimes, prosecute defendants, and punish convicts more efficiently.

To curb gun violence, he advocates "microstamping" firearms, making it easier to trace weapons used in crimes.

By tracking a unique alphanumeric code etched onto the firing pin of a gun, investigators can use shell casings found at crime scenes to trace the gun's origin.

Throughout his campaign, Untermeyer has advocated electronic monitoring for nonviolent convicts and people awaiting trial.

For them, GPS-enabled electronic ankle monitors, which can be leased for $8 a day, are a better alternative than incarceration at $98 a day, he said. For a month beginning in September, Untermeyer wore an electronic anklet to demonstrate its 24/7 tracking power. He linked it by software to his campaign Web site and invited visitors to click the icon marked "Find Mike."

"My opponent [Democratic candidate Seth Williams] has called this a gimmick," Untermeyer said. "The real gimmick is my opponent running for office with virtually one proposal - community courts - that have proven in the past to be unreliable, ineffective, and rife with corruption."

In a contest in which the gloves rarely have come off publicly, that sharp shot was a rarity.

Another blow - this one aimed at Untermeyer - was struck last week. Three prominent African American supporters of Williams', including State Sen. Anthony Williams, held a news conference to blast the GOP candidate for his response to a debate moderator's question about racial bias and the death penalty.

"There is no racial profiling regarding death-penalty sentencing in Pennsylvania," he said in the televised debate two weeks ago.

Citing a 2003 Pennsylvania Supreme Court study that found "strong indications that Pennsylvania's capital justice system does not operate in an evenhanded manner," Sen. Williams accused Untermeyer of lacking the racial sensitivity required of a top prosecutor in an ethnically diverse city.

Ever feisty, Untermeyer showed up at the news conference unannounced to defend himself. He branded the accusation "a smoke screen" meant to obscure the campaign's substantive issues.

A few hours later, he appeared at a candidates' forum sponsored by the Philadelphia chapter of the National Coalition of 100 Black Women Inc., a service group.

There he gave his side of the dustup, telling the group that while the justice system may not be bias-free, "I don't think the D.A.'s Office profiles African Americans to put them on death row." He received applause.

Heading to his car after the meeting, he said, "When I came here tonight, I didn't know what I would be facing." But the follow-up questions - about electronic monitoring, the difficulties of fighting drug crime - had focused on substantive issues, and that, he said, left him encouraged.

A former deputy state attorney general, and assistant prosecutor in Philadelphia from 1980 to 1984, Untermeyer ran unsuccessfully for Philadelphia sheriff as a Democrat in 2007. He switched parties to run for D.A. as a Republican, he said, to distinguish himself from the crowd in the five-man Democratic primary. He ran unopposed on the Republican ballot.

If the predicted low turnout in the general election comes to pass, the race might be won with just 75,000 votes.

"When I ran for sheriff 21/2 years ago I received 62,000 votes. If I receive half of those voters again, and all the Republicans who vote, that will get me to the 75,000 mark," he said.

"Does low turnout help me or hurt me? Ask me that question next Tuesday night."

For more about Michael Untermeyer, read a profile at http://go.philly.com/untermeyer