Arlington, Virginia (CNN) -- Too many motorists stopped for suspected alcohol impairment have found that just saying no to a request for a roadside breath test improves their odds of beating a conviction, federal authorities say.
"We know that refusing a breathalyzer is a persistent, ongoing problem," said U.S. Transportation Secretary Ray LaHood. "There's a loophole here."
Announcing a "no refusal" strategy Monday as part of a holiday crackdown on drunken driving, LaHood said the federal government is advising law officers to use a search warrant to quickly obtain a blood test from drivers who have refused to take a breath test.
"We know people are going to try and find ways to get out of very bad, dangerous behavior," he said, "and we're not going to let that happen."
The strategy -- already being used in nine states -- involves having local judges on call for requests from police for a search warrant in a suspected case of alcohol impairment, just as is done to authorize a search for illicit drugs during a traffic stop. Only in this case, the blood test is the means of obtaining evidence.
Additional personnel trained in blood collection also are part of the effort.
LaHood, at a news conference held in the lobby of the Arlington County Detention Center, was flanked by a variety of state and local police officers from around the country, some of whom told reporters their testing of the program is already showing it to be a success.
Sheriff Craig Webre of Lafourche Parish, Louisiana, told reporters that if drivers "refuse to submit to a blood-alcohol test, the deputy will apply to the court for a search warrant, ordering the subject to submit to a blood test."
"This process enhances the ability of the prosecutor to close loopholes and criminally prosecute drunk drivers," he said.
The law supports the strategy in some 30 states, but most of them are not currently using the warrant initiative, officials said.
Meanwhile, based on 2005 figures, nearly one in four suspected drunken drivers refuses a breath test, according to an average of reports from 38 states.
LaHood blames defense attorneys who counsel repeat offenders to avoid providing scientific evidence -- the results of a breath test -- that could help convict them when a drunken driving case comes to trial. "The only way to really get these folks off the road is to go to this kind of a program," he said.
Texas prosecutor Warren Diepraam said nearly half the drunken drivers in his jurisdiction refused a blood or breath test before authorities tried the warrant strategy. "During a no-refusal night, our refusal rates dropped to about as low as 10%," he said, with those refusing then subject to a judge's order.
"We have found that the people who refuse are typically our most dangerous DWI offenders," Diepraam said, and that "50% of those people have additional intoxicating substances in their system."
"Because of the program," he said, "we now give 100% scientific evidence to our juries in Montgomery County, Texas."