Seattle police have found that drunken-driving arrests were routinely rubber-stamped or falsely certified without approval by a supervisor, prompting one defendant to ask a judge to dismiss his case or suppress the arresting officer's testimony.

The department launched an internal investigation in March after an audit revealed the mishandling of dozens of driving-under-the-influence (DUI) cases.

A sergeant who allegedly permitted the improper screening remains under investigation.

But the department has found that two members of the DUI Unit, Jonathon Huber and Jonathan Young Jr., routinely used the sergeant's signature stamp without having their arrests approved by him as required by policy, according to an internal-investigation report obtained by The Seattle Times.

A third officer, John Velliquette Jr., put written statements in his reports indicating his sergeant had screened his arrests, even though the sergeant had not actually reviewed the cases, the June 22 report said.

Witnesses indicated the sergeant told the officers he had "preapproved" their arrests and offered his signature stamp, according to the report.

The three officers were cleared of misconduct allegations involving honesty and arrest procedures after the department's Office of Professional Accountability (OPA) heard testimony that the practice had been going on for 20 to 25 years and that most law-enforcement agencies do not require DUI arrest screening because most suspects are released after processing.

Witnesses also said the stamp was used to satisfy data requirements and not to deceive.

According to the report, the OPA also considered DUI officers the department's "experts in the identification, arrest, processing and courtroom presentation of evidence" and that "it is unnecessary to have a [sometimes] less knowledgeable sergeant reviewing their reports."

Although the allegations were not upheld, all three officers were ordered to undergo supervisory counseling and training for violating the department's arrest-screening policy. They were put on desk duty when the investigation began, but they have been returned to DUI patrols.

The OPA originally found Velliquette had been dishonest and gone further than the other officers by submitting written information that was false. But Deputy Chief Nick Metz determined supervisory intervention was more appropriate. OPA Director Kathryn Olson concurred.

Supervisory intervention means that while there may have been a violation of policy, it was not a willful violation that amounted to misconduct, according to the department.

"Because this appears to be a distinction of form rather than substance, and given the past practice situation and lack of any intent to deceive, it is appropriate to make a Supervisory Intervention finding on Honesty for all three named officers," Olson wrote in the report.

Olson also wrote that, "in no uncertain terms, the employees should be reminded of the need to follow Departmental policy and to question direction from a superior to the contrary."

She also recommended the traffic section conduct regular audits of DUI Unit arrest-screening procedures.

Seattle police declined to disclose the names of the officers or details of the internal investigation under a public-disclosure request filed by The Times, citing its policy of not releasing that information in cases where officers have been cleared of wrongdoing.

The Times independently obtained a copy of the findings from Stephen Hayne, a longtime DUI attorney in Bellevue.

Another attorney, Joseph Richards, a public defender with Associated Counsel for the Accused, is representing defendant Luis Ivan Negrete Ramos in his effort to win dismissal of his case or suppression of the officer's testimony.

Richards declined Friday to discuss the request.

If granted, the motion could open the door to other legal challenges of DUI charges in Seattle.

But Hayne said it is unlikely the judge would dismiss the case or suppress testimony, instead leaving it to a jury to decide the credibility of the officer.

The officer can be cross-examined by the defense while remaining competent to testify, Hayne said.

A hearing on the request has been set for Thursday before Seattle Municipal Court Judge Steve Rosen.

Craig Sims, chief of the criminal division in the City Attorney's Office, said Friday that prosecutors are preparing a response to be disclosed at the hearing.

Sgt. David A. Abe has been identified by sources as the sergeant who was placed under internal investigation.

One allegation is that Abe routinely did not report to work, according to a source.

In March, the president of the Seattle Police Officers' Guild, Sgt. Rich O'Neill, called the investigation an unfair reaction to a "paperwork snafu."

At that time, DUI cases involving the three officers were put on hold pending the outcome of the internal investigation. The hold was lifted a few weeks ago, allowing the officers to testify with their credibility subject to cross-examination, Sims said.

Information from Times archives is included in this story.

Steve Miletich: 206-464-3302 or smiletich@seattletimes.com