HARRISBURG -- A House intern spent part of a summer two years ago erasing computer hard drives and destroying e-mail backup tapes that were later sought as part of the attorney general's investigation into the payroll bonus scandal.

That account and several others are detailed in an investigation report that gives day-by-day progress in the case that later became known as "Bonusgate." The report was attached to a pretrial motion by one of the 12 defendants in the case. While lengthy sections are blacked out, the Post-Gazette obtained a complete copy of the document which at once offers glimpses inside the still-unfolding case and raises questions about possible future charges of obstruction.

At points, agents from the office of Attorney General Tom Corbett engaged in a cat-and-mouse pursuit of some top House staff members, subpoenaing surveillance videotapes that showed one rolling a cart of computers out of his office and into a parking garage. At another juncture, agents investigating former House Minority Whip Michael Veon, D-Beaver, also turned their attention to an authority in the district of former House Majority Leader H. William DeWeese. Investigators subpoenaed records from the Greene County Industrial Development Authority, but apparently found nothing out of order.

The portions of the document kept out of the public eye sketch a series of incidents that suggest a scramble to erase evidence as the probe into the bonus scandal got under way. Prosecutors were able to recover only a handful of e-mails from the House Democratic Caucus in their investigation, and an account given by Tyrrell S. Drew, of Mt. Holly, Dauphin County, a former intern in the Democratic Department of Information Technology, suggests why.

Mr. Drew, then a student at Harrisburg Community College, interned at DIT from December 2006 through April 2007, and again from August 2007 to January of last year.

Interviewed by agents in January of last year, Mr. Drew said he was instructed to take five computer hard drives to another Capitol office and erase them with a large magnet. Mr. Drew said he was told by Steve Keefer, then the director of the office, "that the process would clean the hard drives so they could be reused. Drew explained to [state investigators] that it is his personal belief that a magnet as strong as the one he used would completely destroy a hard drive, leaving it useless to anyone."

When Mr. Drew brought the hard drives back to the office, he said he encountered a worried reaction from Darryl Hazelwood, Mr. Keefer's deputy.

Mr. Drew said "Hazelwood went to Keefer's office 'in a panic' and reported the hard drives were not completely erased," according to the report.

Mr. Drew said he was sent back to complete the erasures.

Mr. Hazelwood yesterday said he could not discuss the incident.

"Right now is probably not the best time to discuss those topics because there's still an ongoing investigation," he said.

Between February and April of 2007, Mr. Drew told agents, he was instructed by another DIT administrator to run a hand drill through e-mail backup tapes.

With backup tapes gone, investigators were stymied for a time in their attempt to establish a direct link between millions of dollars in year-end bonuses paid to House Democratic employees and their work in the 2006 campaign that gave their party control of the state House.

Investigators were later able to obtain partial records from May 2007 and a full set from the following October, but most e-mails relating to the bonuses prior to that had been deleted from the system.

An early indication of the efforts to clean records was provided by a confidential informant inside the Legislative Research Office.

After 20 boxes were seized in a raid there in August 2007, the informant told investigators of one staff member inside the office consulting with technicians about how to turn off the automatic archive in his office computer.

Other computers were taken from the Capitol building rather than destroyed, investigators learned from an Information Technology Department employee who reported seeing co-worker David Fitzkee wheel a cart full of computer equipment through the Capitol to an underground parking garage. Investigators obtained security surveillance tapes showing Mr. Fitzkee load the equipment into a parked car on Dec. 15, 2007.

When investigators approached Mr. Fitzkee 19 days later, he first said he never took equipment out of the Capitol, but later he remembered that once took a computer home to test a new operating system "because he was tired of staying until 8-8:30 p.m. doing the work."

Investigators followed Mr. Fitzkee from Harrisburg to his home in Lebanon. He refused to let them inside "for reasons of cleanliness and two large dogs," but turned over two computers, two hard drives, a card reader and a data board, which investigators admitted into evidence in the Bonusgate case.

Mr. Fitzkee could not be reached and his attorney did not return a phone call yesterday.