OKLAHOMA CITY ? Michael Fortier, the federal government’s star witness at the bombing trials of Timothy McVeigh and Terry Nichols, is expected to testify for Oklahoma prosecutors when a preliminary hearing for Nichols begins its second week.

Fortier, a close friend of McVeigh’s who met him in the Army, pleaded guilty to bombing-related charges in August 1995. He has admitted helping McVeigh move and sell stolen guns and of lying to FBI agents after the April 19, 1995, attack that killed 168 people.

McVeigh joined Fortier in his hometown of Kingman, Ariz., in 1993 and lived there intermittently for two years. His last job was in Kingman, loading purchases at a hardware store.

At McVeigh’s trial, Fortier testified that McVeigh showed him a truck-bomb diagram while seeking his help in testing explosives for the attack.

Testimony at Nichols’ preliminary hearing indicates Nichols also visited Kingman. The hearing, which began May 5, was scheduled to resume Monday.

Fortier, 34, was sentenced to 12 years in prison for knowing about the Oklahoma City bombing plot and not telling authorities. Fortier’s wife, Lori, also testified for the government at the federal bombing trials. She served no jail time.

Fortier is being held in a secret location by the Federal Bureau of Prisons.

The preliminary hearing will determine whether there is enough evidence to try Nichols, 48, on 160 state counts of first-degree murder and seek the death penalty for the bombing of the Oklahoma city federal building.

Nichols already is serving a life prison sentence on federal conspiracy and involuntary manslaughter convictions for the deaths of eight law enforcement officers in the bombing. The state charges involve victims who were not part of Nichols’ federal trial.

Prosecutors allege that Nichols and McVeigh, who became friends while serving in the Army, participated in a series of robberies and thefts to raise money and assemble components of an ammonium nitrate and fuel oil bomb that was detonated outside the federal building.

Nichols was at home in Kansas the day the bomb exploded. But prosecutors said he helped McVeigh deliver a getaway car to Oklahoma City and worked with McVeigh to pack the 4,000-pound bomb inside the truck the day before the bombing.

McVeigh was convicted on federal murder charges and executed in June 2001.