A former D.C. police officer was convicted yesterday of tampering with evidence, obstructing justice and other corruption charges stemming from the unauthorized return of a confiscated truck to a suspected drug dealer.

Wallace S. Najiy II, a former vice officer from the 4th Police District, was ordered jailed by U.S. District Judge Thomas F. Hogan immediately after the jury verdict. He faces a maximum term of life in prison at his sentencing Oct. 14.

Prosecutors said Najiy betrayed the public's trust and went on the payroll of a criminal when he provided favorable treatment to Gregory D. White, a Northwest Washington man he arrested on a narcotics charge in September 1995.

Najiy, 36, who denied wrongdoing, did not testify during the trial. He resigned after his indictment in January. Before that, he was on administrative leave while police supervisors attempted to sort out what took place.

Assistant U.S. Attorneys John Moustakas and J. Patrick Rowan contended throughout the two-week trial that Najiy pocketed $500 for arranging the release of White's truck from a police impound lot. Najiy had seized the vehicle from White after discovering cocaine in it. The truck was supposed to be kept for forfeiture proceedings, the prosecutors said. At the time of the alleged payoff, Najiy was going through bankruptcy proceedings.

White ultimately pleaded guilty in the drug case and completed three years of probation. He testified as a government witness in Najiy's trial, saying that he had dealt with Najiy through a middleman, private investigator Clement F. Brown.

According to White, Brown offered his assistance in a meeting at D.C. Superior Court, where the investigator spends much of his working time. White testified that Brown boasted of his friendship with Najiy and said he could get matters "squared away" in return for money. He said he gave Brown three checks totaling $2,800, plus some cash, and got back the truck and a wedding ring that was taken by Najiy at the time of the arrest.

Brown also testified against Najiy, saying he gave the officer $500. Brown, 63, acknowledged in court that he cooperated with prosecutors in the hope of getting a lenient sentence for his role in the case. He pleaded guilty to aiding and abetting in the bribery of a public official.

Much of the case relied on a painstaking review of police paperwork and procedures. Najiy was accused of changing the truck's classification in police property records from "civil forfeiture" to "safekeeping" and then releasing the vehicle to White's father-in-law without obtaining the required approvals.

The jury convicted Najiy of 10 charges and acquitted him of seven others. He was convicted of five counts of forgery, two counts of fraud, two counts of obstruction of justice, and one count of tampering with evidence. He was acquitted of five fraud counts and one count each of bribery and conspiracy.

Najiy's attorney, Michele Roberts, said that Najiy had a history of turning in sloppy paperwork and that the White case was just another example of that problem. She insisted in her closing arguments to the jury that Najiy received no money and had no idea what arrangements Brown was making with White.

Roberts said she was stunned by the verdict and intends to appeal.

White, meanwhile, said he would like to get his money back. He said he felt victimized by Brown and Najiy and hopes that they both wind up in prison.