JEFFERSON CITY • Police in Missouri will have the authority to extract blood samples from suspected drunk drivers without a warrant if a bill given initial approval Wednesday by the Missouri House becomes law.

The legislation includes several measures that would crack down on the most severely intoxicated drivers and enforce better tracking of prior offenses. It would move more drunken driving cases out of municipal courts and into state courts, where the penalties are more severe. And it would allow counties to create special dockets for DWI defendants, which could help authorities better match problem drunks with services they need.

Rep. Bryan Stevenson, R-Webb City — the bill's sponsor — told other lawmakers about his cousin, who Stevenson said had four DWIs on his record, to bring attention to the need for the special dockets.

"It's an addiction and there needs to be treatment," Stevenson said.

The bill, and another like it in the Senate, were filed in response to a Post-Dispatch investigation last year that found that St. Louis-area police, prosecutors and judges often fail to punish drunk drivers. Citing the newspaper's findings, Gov. Jay Nixon last year called for dramatic and immediate changes to a system "riddled with loopholes and dark corners." The governor said in an e-mailed statement Wednesday that the House vote was an "important first step toward DWI reform."

The local chapter of the American Civil Liberties Union said it had tried to lobby the Legislature not to enact the warrantless blood sample seizures, which were pushed for by prosecutors.

"We think that it's unconstitutional," said John Chasnoff, an ACLU program director.

A couple of Democrats, including Rep. Mike Colona, D-St. Louis, unsuccessfully fought against that provision on the House floor. Colona, a lawyer, has represented DWI defendants in court.

Under current Missouri law, a person who refuses a blood-alcohol test is given an automatic one-year drivers license suspension. But the Post-Dispatch found that, many times, prosecutors give those drivers back their license as part of the plea deal in the criminal case.

Peter Joy, a law professor at Washington University, said he expected that aspect of the bill to be challenged.

The bill would also:

• Require drivers with blood-alcohol levels of at least 0.15 percent to spend 48 hours in jail, and of at least 0.20 percent to spend at least five days in jail, unless they complete the requirements of a DWI court or docket.

• Require all municipal judges to complete courses on state drunken driving laws and direct their courts to report all DWI case dispositions to a central databank.

• Require state courts to handle any DWI case involving a defendant with at least two alcohol-related contacts with authorities, or any defendant with at least one previous intoxication-related offense facing another DWI in which someone was injured.

• Require police and prosecutors to adopt policies for reporting information on DWI offenses to a central databank, as a condition of receiving grants from the state Department of Public Safety.

• Increase penalties if a driver's blood-alcohol content is at least 0.15 percent, and prohibits those defendants from getting a plea deal that allows them to avoid a conviction.

• Require prior offenders to serve at least 10 days in jail and persistent offenders to serve at least 30 days.

• Increase the drivers license revocation period from one year to two years for a person who refuses to submit to any blood-alcohol test.

• Allow a first-time drunk driver who doesn't reoffend have his record expunged after 10 years.

The bill needs one more vote to advance to the Senate.