Former Winnebago County District Attorney Joseph Paulus could face an investigation into allegations he withheld or tampered with evidence in dozens of criminal cases, local officials said Monday.

In a separate investigation, the FBI has been probing Paulus since May 2002 after an Oshkosh woman came forward to say she paid her defense attorney, Milton Schierland, $5,000 in cash in 1999 to ensure she wouldn't be convicted of a third drunken driving offense in Winnebago County.

Last week, Paulus resigned from the private law firm where he'd been practicing. Partner Gerald Boyle said Paulus "said enough for me to know he has some very serious, serious trouble" coming "in the next few weeks."

A spokesman for the FBI in Milwaukee wouldn't comment on the investigation.

Paulus didn't return phone calls left at his Oshkosh law office. Schierland, who also worked for a time as an assistant district attorney under Paulus, also didn't return a message left at his Oshkosh law office.

In addition to the federal investigation, Winnebago County District Attorney William Lennon said Monday his office has received "dozens and dozens" of complaints from defendants and defense attorneys alleging misconduct by Paulus, who was Winnebago County's top law-enforcement official for 14 years.

In 2001, Paulus was on short lists of candidates to become the U.S. attorney for the western or the eastern district of Wisconsin.

Lennon said he will wait to see if federal charges are filed to determine whether an investigation into allegations of prosecutorial misconduct is warranted. "I want somebody to look at this stuff," he said.

"What I can confirm is we are waiting to see what the FBI and the U.S. attorney's office files," said Lennon, who defeated fellow Republican Paulus in the 2002 election. "We want to see the scope of their charges. We want to see the scope of their investigation. If we feel there's more ground to be covered, one of the options would be to have a 'John Doe' investigation in this county. Another is to refer it to the attorney general office's Public Integrity Unit."

Assistant District Attorney Mike Balskus said his review of some cases handled by Paulus shows "it's clear that Joe withheld evidence from the defense." Balskus confirmed the cases being reviewed by his office include some of Paulus' most highly publicized efforts as a prosecutor, including at least one murder case. He declined to be more specific.

"We're looking at the way (the cases) were handled and whether or not there were problems with evidence used to obtain convictions," Balskus said.

Balskus said based on his office's contact with federal authorities, the federal investigation appears to be focused on alleged cash-for-leniency deals and possible tax evasion by Paulus.

"I don't think that the feds are interested in (prosecutorial misconduct)," Balskus said. "I think they were interested in money that went into (Paulus's) pocket."

The FBI has obtained information about at least three dozen cases handled by Paulus from 1995 to 2002, including cases involving drug dealing, drunken driving, theft and disorderly conduct. Lennon confirmed that in some cases, the prosecutors' files are missing.

The case that sparked the federal investigation involved Connie Christensen, an Oshkosh woman arrested in 1999 on a tentative charge of drunken driving-third offense. In a sworn statement, Christensen said, "(Schierland) said he talked to some people that owed him favors and that he was 98 percent sure he could get me off because he could pull some strings. He told me for $5,000 he could get me off of this. He said there would be no jail time or assessment, or anything on my record."

Christensen said she saw Paulus give Schierland her case file at the Winnebago County Courthouse. When Christensen's case was called, one of Paulus's assistants asked Judge Barbara Key to dismiss the case, saying the file was missing, the statement said. Court records show Christensen was convicted of reckless driving and paid a fine.

"After the court case, I felt shocked by what I saw," Christensen wrote. "I thought, 'I guess money can buy anything.' "

Paulus lost re-election in 2002 after news of the FBI probe surfaced and one of his political opponents released a tape recording of Paulus bragging about having sex in the district attorney's office. After losing the election, Paulus joined the firm of Milwaukee defense attorney Boyle, who said Paulus "obviously didn't tell me the truth" about the allegations against him.