The Prince George's County police officer on trial for fatally shooting an unarmed college student after a dance was acquitted yesterday by a judge, who said DNA evidence convinced him that the officer had acted reasonably.

Before an Upper Marlboro courtroom packed to standing room with county police officers and relatives of the defendant and the student, Circuit Court Judge E. Allen Shepherd found Officer Brian C. Catlett not guilty of involuntary manslaughter and reckless endangerment in the November 1999 death of Gary Albert Hopkins Jr.

Shepherd's verdict comes at a time when the county police department is under unprecedented scrutiny for alleged excessive force and other forms of misconduct.

Some of Hopkins's relatives wept softly as Shepherd announced his verdict. Catlett, 26, appeared to breathe a sigh of relief but otherwise did not react. The police officers who packed the defense side of the courtroom also maintained stoic expressions as the verdict was read.

Afterward, though, police union chief John A. "Rodney" Bartlett delighted in the news and blasted State's Attorney Jack B. Johnson (D), whom he accused of bringing the case for political reasons amid the furor over police misconduct.

"We're very excited about the verdict," Bartlett said. "We believe Jack Johnson owes an apology to the citizens of Prince George's, the family of Gary Hopkins and especially Brian Catlett."

Johnson said the outcome might have been different if Catlett had gone before a jury, rather than choosing to be judged by Shepherd.

"It would have been good if we had had the citizens of the county sitting as the finders of fact," Johnson said. "I'm not going to argue with the judge's legal conclusion. This was a case that had to be tried. We had overwhelming evidence."

Hopkins's mother, Marion Gray-Hopkins, agreed.

"It's not an unexpected verdict," she said. "I don't think the judge was fair; I think he was very biased. His mind was made up when the trial began. It would have been a challenge for him to step out and convict one of his own; it's the old boy network."

Shepherd cited DNA testimony presented by defense attorneys Robert C. Bonsib and Tara Harrison as critical in his decision.

A DNA examiner from the FBI said she found traces of genetic material belonging to Hopkins under the gun sight of county police officer Devin C. White. Much of the trial's testimony centered on whether Hopkins, 19, grabbed the gun in the moments before Catlett fired a single shot into his chest.

In explaining his verdict, Shepherd noted how several prosecution witnesses testified that they never saw Hopkins touch White's weapon in the moments before the shooting. Some said Hopkins had his hands in the air when the shot was fired.

Shepherd cited testimony by Tamila Keith, a friend of Hopkins's, who said she saw no contact between Hopkins and White before the shot was fired.

"That is directly contradicted by the DNA evidence in this case," Shepherd said.

Shepherd did not address an argument made by Assistant State's Attorney Roland Patterson, who, in an impassioned closing argument yesterday, said that the DNA evidence was irrelevant if Hopkins had let go of the gun and raised his hands at the moment Catlett fired.

Police training experts who testified for the state and for the defense had agreed that in such a scenario, a police officer would not be justified in firing his weapon.

Yesterday, police officials said only that their internal investigation into the case would be finished shortly.

In the meantime, the Justice Department is conducting a broad probe into whether Prince George's officers routinely use excessive force and whether such actions go unpunished. That investigation grew out of an ongoing FBI probe into whether the police department's canine unit engages in a pattern of excessive force.

Two county police officers, former members of the canine unit, are scheduled to go on trial in U.S. District Court in Greenbelt next week on charges that they violated the federal civil rights of an unarmed homeless man by setting a police dog on him.

In recent weeks, Johnson has said he will no longer use as witnesses for the state two county police officers involved in high-profile cases, saying he cannot vouch for their truthfulness.

One of those officers is White, who, under cross-examination, admitted that he had been untruthful in a sworn deposition about the Catlett shooting that he gave to an attorney for the Hopkins family, which has filed an $80 million federal civil suit against Catlett, White and the police department.

Last year, civil juries awarded plaintiffs more than $6 million in trials involving county police brutality and other misconduct.

Catlett and his supporters left the courtroom through a back exit, avoiding reporters.

Bonsib, Catlett's lead attorney, said: "The nightmare is over for Officer Catlett. This prosecution was ill-advised from the very beginning." If the DNA evidence had been presented to the grand jury, Bonsib said, there would have been no indictment.

Johnson said the DNA evidence was not presented to the grand jury because White's gun was not taken by the FBI until four months after the shooting, leaving time for potential tampering.

Catlett shot Hopkins about 2:30 a.m. Nov. 27, 1999, outside the parking lot of the West Lanham Hills fire station after a dance. According to court testimony, Catlett radioed for backup when a fight broke out between two groups of men in two cars. Hopkins was in one of the cars.