CALIFORNIA ELECTIONS : SAN DIEGO COUNTY D.A. : 2 Republicans Slug It Out in Wide-Open Race : Ex-prosecutor Paul Pfingst and Judge Larry Stirling may be in the same party, but they disagree on a raft of issues, from “three strikes” to how to collect child support from deadbeat dads.

Here is a full list of the things that Paul Pfingst and Larry Stirling, candidates for district attorney of San Diego County, agree on: Proposition 187.

Both are against it, although for different reasons. Pfingst, 43, a former prosecutor, says it is unconstitutional; Stirling, 52, a municipal judge, says it is too expensive.

Here is a partial list of the things Pfingst and Stirling disagree on:

* Proposition 184, the “three strikes and you’re out” measure.

* What to do about teen-agers with guns.

* How best to collect child support from deadbeat dads.

* Whether the county needs a 24-hour court for abusive spouses.

* Whether endorsements from law enforcement groups mean anything.

* Whether the district attorney should be a prosecutor or a systems manager.

* Who should investigate shootings involving police officers.

* Whether Pfingst is fudging on his resume by saying he supervised the biggest homicide team around.

* Whether Stirling was an ace crime fighter or a lackey of the National Rifle Assn. when he served in the Assembly and state Senate.

From this collision of ideas and passions, San Diego County voters must do something they have done only twice in the last half-century: select a new district attorney.

After serving 24 years, Dist. Atty. Edwin L. Miller Jr. was crushed in the June primary in the wake of a failed prosecution in a high-profile case that the county grand jury said smacked of a witch hunt. Before Miller, the job was held by James Don Keller, who served 24 years before retiring.

The choice between Pfingst and Stirling, or maybe the whole notion of picking a new district attorney, appears to have flummoxed voters.

A poll released Wednesday by the San Diego Union-Tribune and KNSD-TV showed 22% of voters for Stirling, 21% for Pfingst and 55% undecided. (In the primary, Pfingst got 31% and Stirling 23%.)

The poll energized the combatants, both Republicans.

The Stirling campaign began furiously leaking documents, trying to pick away at Pfingst’s reputation as a tough but principled prosecutor, a reputation made largely on his successful prosecution of California Highway Patrol Officer Craig Peyer for the murder of a female college student during a traffic stop.

Pfingst went on the attack during a debate on KFMB-TV, attempting to hold Stirling responsible for the Legislature’s failure to pass anti-crime legislation during his nine years in Sacramento.

Whoever wins, something is coming to law enforcement that voters in the past have shown little appetite for: change.

“This is the first time in 25 years we’re going to be able to overhaul the criminal justice system,” Stirling said.

Pfingst had been considered the clear front-runner because of his strong showing in the primary, his endorsements from the Union-Tribune, KNSD and law enforcement groups, and his celebrity from the Peyer case and a short stint as a legal commentator on television.

He has hammered at the theme that the district attorney should be a prosecutor (Stirling has never been a prosecutor), that the county should step up collection from deadbeat dads rather than hire a private agency (as Stirling suggests) to enforce court-ordered child support, and that the district attorney, not city councils, should investigate officer-involved shootings.

He has criticized Stirling for his refusal to “stand up to the NRA.”