AURORA, Colo. -- Jury selection is under way in the Sir Mario Owens murder trial.

Owens and two alleged accomplices, Robert Ray and Parish Carter, were indicted two years ago in the double slaying of Javad Marshall Fields and Vivian Wolfe.

The young college graduates, who had just become engaged, were gunned down June 20, 2005, in the intersection of South Dayton and Idaho.

Investigators believe the victims were killed because Fields was slated to testify as a key witness in another murder case involving Owens.

The defendant was found guilty in that case and is serving a life sentence. If convicted of killing Fields and Wolfe, Owens could get the death penalty.

Arapahoe County District Attorney Carol Chambers cited several aggravating factors when she came to her decision to pursue the death penalty -- among them, committing a felony for monetary gain, knowingly causing death to another person in addition to the victim and committing the offense for purpose of avoiding or preventing lawful arrest or prosecution.

Jury selection is expected to take three or four weeks. Opening statements are slated for March 28.

"That's not unusual," said former Adams County District Attorney Bob Grant.

Grant said it takes longer to seat a jury in a death penalty case for two main reasons: First, judges have to make sure no one makes a decision based on what he or she has seen on TV or read in the newspapers. "Potential jurors have to be questioned individually, so their responses don't taint other potential jurors," the former prosecutor said.

Second, jurors have to be death penalty-qualified. "There are some people who have very strong feelings, who could never impose the death penalty," Grant said. "There are some people who have feelings the other way who say, 'It doesn't matter what the law says; if he's guilty, I'd impose the death penalty automatically.' Those two extremes of people have to be taken out of the mix."

Grant said it took three to four weeks to seat juries in both the Robert Harlan and Gary Davis cases.

Harlan was convicted of murdering Rhonda Maloney in 1994. He followed her home from work in Central City and then rammed into her car near Interstate 25 and Interstate 76.

She got out, fled and was picked up by a good Samaritan, who drove straight to Thornton police headquarters. Harlan gave chase and fired several shots along the way. One of them paralyzed the good Samaritan, Jackie Creazzo. Harlan then kidnapped Maloney, assaulted her and killed her. Her body was found several days later under a bridge along Imboden Road east of Denver International Airport.

Davis was put to death in 1998 for the 1986 kidnapping, rape, torture and murder of Ginny May in Byers.

He was the last person executed in Colorado.

Since then, Colorado experimented with letting a three-judge panel decide whether to sentence a convicted murderer to death.

A Supreme Court ruling struck down that experiment, so death penalty decisions are now back in the hands of jurors.

"You've got to bring in about 200 people to get 12 jurors and four alternates," Grant said.

The difficulty then shifts from attorneys to the jurors themselves following opening statements.

"You've got people being asked to make life-and-death decisions," the former district attorney said. "And they're not professional decision-makers. They're just people, folks off the street. It's emotionally draining; it's physically draining. It's the hardest thing that jurors can do."

Three sets of jurors will face that task in Arapahoe County.

Robert Ray’s trial is scheduled to start Aug. 18, and Parish Carter’s trial is slated to begin Feb. 2, 2009.

When asked about the cost of death penalty cases, Grant said, "They're expensive, but it's a cost that, I think, society willingly bears in those few cases where it's determined that the defendant should look the devil in the eye."