DURHAM, N.C. — Prosecutors said Thursday that new evidence discovered on one of the computers seized from Robert Petrick's home proves that he planned his wife's death.

During court proceedings, Assistant District Attorney Mitch Garrell told Superior Court Judge Orlando Hudson that a forensic investigator discovered Wednesday evening that four days before Petrick's wife, Janine Sutphen, was reported missing Jan. 22, 2003, Petrick extensively researched lake levels, water currents, boat ramps and access, as well as topographical information about Falls Lake.

In May 2004, two fishermen discovered Suthpen's body floating in the Raleigh lake. It had been wrapped in tarps and blankets, tied up in chains and bound with duct tape.

Petrick, who is representing himself in the trial, argued that the new evidence should not be allowed in the trial, telling the judge that prosecution had nearly three years to disclose the evidence they found and that the last-minute move was unfair. Hudson, however, disagreed and allowed the new evidence into trial.

Even as testimony is set to begin next week, investigators are still sifting through material seized from nearly a dozen computers from Petrick's home. Investigators said the contents of the computers' hard drives is equivalent to about 100 million pages -- enough to fill 12 tractor-trailers.

Petrick is currently serving a prison sentence for a fraud conviction. Prosecutors and police say that conviction is connected to the murder charge, but they have not said how.

If convicted of first-degree murder, Petrick would face the possibility of life in prison.