A man accused of impersonating a lawyer in at least 10 states was convicted Wednesday of mail fraud and making false statements in what a government lawyer hoped would be the first of several federal prosecutions around the country.

It took only about an hour and a half for a federal jury in Bismarck to convict Howard O. Kieffer, who shrank in his chair and gulped as the verdict was read.

Authorities said Kieffer lied on his application to practice law in federal court, but still represented such clients as a former St. Louis Blues hockey player who pleaded guilty to plotting to kill his agent.

At the trial, two witnesses told the jury they each paid Kieffer at least $20,000 to appeal prison sentences for their loved ones, only to find out later that he wasn't a lawyer. Attorneys testified that they thought Kieffer was one of their colleagues because he seemed to know about federal court matters and because they saw him at attorney training seminars.

Kieffer's attorney, Joshua Lowther, called no witnesses, but he said the government did not prove its case beyond a reasonable doubt.

The 54-year-old from Duluth, Minn., faces up to 25 years in prison and a $500,000 fine; a sentencing date was not immediately set. Assistant U.S. Attorney David Hagler said Kieffer could be prosecuted in federal court in other states where he posed as a lawyer.

"I hope there are other districts in this country that will pursue something," Hagler said immediately after the two-day trial.

Cases Kieffer handled outside North Dakota include that of former St. Louis Blues player Michael Danton, who pleaded guilty in 2004 to plotting to kill his agent.

Kieffer was charged in North Dakota last year after one of his clients, a man accused of child pornography, wrote to a federal judge in Bismarck, raising questions about whether Kieffer had ever been a licensed attorney.

Hagler said no one checked Kieffer's credentials.

"They thought he was a lawyer and they trusted him," Hagler said as the trial began. "A lot of people made that mistake."

Court records show Kieffer was convicted earlier of theft and filing false tax returns and served time in a federal prison from 1989 to 1992.