In 2003, the Allegheny County coroner's office bustled with routine work -- pathologists conducting autopsies, histologists creating tissue slides and deputy coroners tracking down next of kin.

But according to federal prosecutors, it also hummed with another type of activity -- that of then-Coroner Dr. Cyril H. Wecht handling cases for his private, multimillion-dollar pathology business.

During the 13th day of Dr. Wecht's criminal fraud trial in U.S. District Court, the prosecution used the pathologist's own schedule to show that he regularly conducted meetings and teleconferences involving his private cases during the workday from his county office.

Those cases resulted in thousands of dollars streaming into Dr. Wecht's private business, money he generated during meetings held on the row office premises or through calls using county phone lines.

To make the government's case, Assistant U.S. Attorney James Wilson spent hours with Eileen Young, the former coroner's top administrative assistant, going over in exhaustive detail the first eight months of Dr. Wecht's 2003 calendar.

Entry after entry indicated the appointments -- sometimes as many as four in a day -- that took place at the coroner's office.

It was the fourth day on the stand for Ms. Young, 61, and she is expected to return Monday as the government's witness when the trial resumes. She is testifying under a grant of immunity.

So far, Ms. Young has played an instrumental role for the government in tying together information key to its allegations -- that Dr. Wecht defrauded his private clients for limousine rides that never took place, schemed to overcharge them for plane tickets that cost him far less than what he billed and used county resources to run his private business.

Ms. Young kept Dr. Wecht's schedule. Despite being a full-time county employee, she has acknowledged she also handled many of the bookkeeping affairs for Cyril H. Wecht & Pathology Associates. She dealt with client intake, managed ledgers, issued checks and sent invoices.

In at least two cases presented yesterday by the government, Dr. Wecht paid a mere $5 for airplane tickets using his frequent flier mileage. In those cases, however, he charged his private clients for airfare expenses totaling $1,018.40 in 2005 and $844.70 in 2004.

In one case involving a consultation for the Church of Scientology, Dr. Wecht authorized Ms. Young to send an invoice that overcharged for an airline trip by $686, plus $80 for a limousine ride he never took. Over the next few years, Dr. Wecht would earn roughly $75,000 from the same client for his services.

Documents presented yesterday by Mr. Wilson indicated that Dr. Wecht billed area district attorneys for mileage covering trips he said he made to their offices, likely using his county car which was running on gasoline also purchased by the county.

Ms. Young testified that Dr. Wecht told her he charged for fictitious limousine rides and mileage for those trips in county vehicles to cover incidental expenses such as tolls, parking meters, parking tickets and even toiletries he had to buy while out of town.

With a document on the screen showing an invoice for "incidental meals," Mr. Wilson went on the attack.

"You knew how to spell incidental, didn't you?" Mr. Wilson asked. "It's not spelled l-i-m-o, is it? ... Did Dr. Wecht ever explain to you why you couldn't spell 'incidental' if that's what you meant?"

"I was never forbidden to type anything that I chose to. If that's the term I chose to use, that's my term," Ms. Young replied.

"Didn't you say that using the limo invoices bothered you?"

"Yes."

"And so you wanted to talk to Dr. Wecht about it?"

"That's correct."

"And his explanation to you was that the phrase 'limo charges' was going to be used for incidental expenses, correct?"

"Yes."