In the richest congressional district in the Pacific Northwest, a two-term sheriff who collared an infamous serial killer is struggling to put away a radio talk show host.

Coming into the fall campaign, King County Sheriff David G. Reichert seemed to have everything going his way. He is a local hero and household name, having led the 20-year investigation that caught and last year coaxed a confession out of Gary Ridgway, the Green River killer.

A Republican, Reichert is running in a suburban House district -- east of Seattle and home to high-tech moguls such as Microsoft co-founder Bill Gates and founder Jeff Bezos -- that has always been represented by a Republican. His Democratic opponent, local radio talker Dave Ross, is well known but has never held elective office.

The district's retiring six-term incumbent, Rep. Jennifer Dunn (R), is throwing her political weight behind the sheriff, who presents well on the stump -- tall, ramrod posture, great hair. The National Sheriffs' Association gave him the 2004 Sheriff of the Year Award. And the Republican Party -- intent on holding on to one of the handful of House seats regarded as genuinely competitive -- is investing heavily in TV ads (more than $1 million by the end of September, with much more planned) that support Reichert and attack Ross.

The sheriff, though, is not walking away with the election. The Cook Political Report views the House race here as one of just 12 in the country that are too close to call. Local analysts say Reichert may be coming across as too conservative for a highly educated, increasingly prosperous district that has drifted Democratic in recent years. It twice voted for Bill Clinton and went for Al Gore in 2000, and pollsters say John F. Kerry has a substantial lead in the district over President Bush.

Unlike Dunn, a fiscal conservative, social moderate and savvy student of the eco-friendly orthodoxies of the Seattle suburbs, Reichert, 54, toes the national Republican line on most social and environmental issues. He is against legalized abortion, against federal funds for embryonic stem cell research and for drilling in the Arctic National Wildlife Refuge.

"He seems well to the right of Jennifer Dunn," said H. Stuart Elway, a veteran Seattle pollster. "It is somewhat surprising that the Republicans would run such a conservative campaign in that district."

Into this opening comes Ross, whose sonorous voice and "common sense" persona have been a popular presence on the radio here for 17 years. The chairman of the state Democratic Party sought Ross out this spring, when, after Dunn announced her retirement, the 8th Congressional District suddenly seemed in play.

Ross's name recognition rivals Reichert's. To give it an extra boost, Ross kept talking on the radio for about two months this summer after he announced his candidacy. The state Republican Party has complained to the Federal Election Commission about an unfair advantage, but an official response is not expected until after the election.

Ross, 52, who says he had no party affiliation until the Democrats came calling, has emerged as a moderate-to-liberal candidate whose issues -- increased access to health care, deficit reduction and a smarter approach to fighting terrorism -- echo those of Kerry.

He also seems to have a feel for the green ethos that colors politics in the Seattle area. He drives a Toyota Prius, a gasoline-electric hybrid, and loves talking about it.

"Nothing would scare OPEC more than 290 million people who are getting 47 miles a gallon," Ross said in a debate last week, as he explained why he believes conservation is a better energy strategy than drilling in pristine parts of Alaska. Ross has picked up the endorsement of Seattle's two daily newspapers.

As far as actual experience that would help him in Congress, Ross points to his world travels and his many combative conversations on the radio. "Dave has debated communism with real communists, jihad with real jihadists and the Iraq war with real Iraqis," his Web site says.

For more than a decade, Ross also did a daily national commentary for CBS Radio. Until he gave it up for politics, it was carried by 244 affiliates nationwide, including WTOP in Washington, D.C.

The sheriff, meanwhile, says he's a doer, not a gabber. Referring to the 1999 riots in Seattle during a meeting of the World Trade Organization, Reichert said, "I was on the streets while Mr. Ross talked about it on the radio."

Still, if aggressive TV attack ads and over-the-top mailings are a measure of political concern, the National Republican Congressional Committee may be worried that Reichert's campaign needs help.

A new TV spot this week, which was paid for by the committee, says that Ross's plan to cut $100 billion in defense spending would "empower terrorists to attack again." The ad does not mention that what Ross wants to cut is a missile defense system that is unrelated to the fight against terrorism and has been criticized by many mainstream military analysts as unworkable.

Fliers that the Republican committee recently mailed to voters in the 8th District include a devilish image of Ross that is framed in red and a Soviet-era propaganda photo of a military officer. The fliers charge that Ross has "radical" ideas that only a communist would love.

In an appearance with Ross in Seattle this week, Rep. Nancy Pelosi (D-Calif.), the House minority leader, contended that the attacks are a sign of Republican "desperation."

But the Democratic Congressional Campaign Committee, too, is spending heavily here, buying TV spots that attack Reichert for his opposition to abortion and stem cell research. Pelosi said more anti-Reichert ads are in the pipeline. "We will be competitive," she said.

Sheriff David G. Reichert is backed by retiring Rep. Jennifer Dunn.Talk show host and political neophyte Dave Ross is running as a Democrat.