The prosecution rested its case Friday in the trial of Oklahoma City bombing (search) conspirator Terry Nichols (search), who could be sentenced to death if convicted of state murder charges.

In a case that spanned 29 days of testimony from 151 witnesses, prosecutors presented evidence they say links Nichols to the bombing of the Oklahoma City federal building, the worst act of domestic terrorism in U.S. history.

The final state witnesses Friday were doctors who performed autopsies on victims of the bombing. They testified about how some of the victims of the bombing died, including decapitation and traumatic injuries such as severed limbs and skull fractures.

The April 19, 1995, bombing of the Alfred P. Murrah Federal Building killed 168 people and injured more than 500 others.

The focus of Nichols' trial now turns to the defense, which will begin presenting evidence Thursday. As many as 200 witnesses could be subpoenaed to testify in Nichols' defense, which attorneys estimate could last three weeks.

Jury selection for Nichols' trial began on March 1. If he is convicted, the trial will move into a separate phase in which jurors will decide whether Nichols is sentenced to death or life in prison.

Nichols, 49, is serving a life prison sentence after a federal jury in 1997 convicted him of conspiracy and involuntary manslaughter in the deaths of eight federal law enforcement agents in the bombing.

In Oklahoma, Nichols is charged with 161 counts of first-degree murder for the deaths of the other 160 victims and one victim's fetus.

Nichols was at his home in Herington, Kan., when the 4,000-pound fertilizer bomb was detonated. But a cavalcade of prosecution witnesses linked Nichols to the bomb plot.

The state's star witness, Michael Fortier, testified over three days that bomber Timothy McVeigh (search) told him Nichols was deeply involved. Fortier, McVeigh and Nichols met in the Army.

Prosecutors allege Nichols helped McVeigh gather bomb components and helped pack the homemade device into the cargo bay of a Ryder truck. Fortier said McVeigh told him that Nichols also robbed an Arkansas gun dealer to help finance the plot.

McVeigh was convicted on federal murder charges and executed in June 2001. Prosecutors called 137 witnesses in 18 days at his trial.

Fortier is serving a 12-year sentence for knowing about the bomb plot and not telling authorities.