Sometime after 12:01 a.m. Friday, Arthur Gary Bishop will be strapped to a gurney and his right arm punctured by an intravenous tube, through which a deadly mixture of potassium cyanide will flow to cause his death.He will die for the murders of five Salt Lake County boys, murders to which Bishop has repeatedly confessed. He says he is ready to die for those murders.

But could there have been other victims? Bishop has repeatedly answered an unequivocal "No."

Despite Bishop's repeated protestations of innocence, law officers say he remains their best suspect in the unsolved murders of Rachael Runyan of Sunset and Thomas J. Walling of Box Elder County.

Sunset Police Lt. Phil Olmstead has spent the last six years trying to solve the 1982 abduction and murder of the 3-year-old Runyan girl. The killing occurred between the deaths of Danny Davis in 1981 and Troy Ward in 1983 - both of them Bishop homicide victims.

"Is it just coincidence that we have a killing a year from 1979 to 1983, and then after Bishop is arrested the killings stop?" asked Olmstead. "I don't think so. But he looked me straight in the eye as he said, `If I did it (illed Runyan), I'd tell you.' "

Olmstead remains unconvinced. The circumstantial evidence points toward Bishop.

Just before the Runyan child was abducted, the kidnapper approached Rachael and her two brothers in a Sunset playground. He even got down and played with them awhile, then offered them candy if they would walk over to his car.

The offer of candy was made particularly to Rachael's 5-year-old brother (ho was of the gender and age group

Bishop preferred). After making the offer, the man turned and left without waiting to see if the children would follow. Only Rachael did.

Olmstead said the technique used in the Runyan abduction and the Danny Davis abduction the year before (o which Bishop confessed) are "exactly the same" and more than mere coincidence.

And the offer of candy to lure a child was also identical to the Alonzo Daniels abduction in 1979, Bishop's first killing.

The detective speculates that Bishop tried to lure the 5-year-old boy, but when he found the girl had followed him about 100 yards to his car, he panicked. He didn't know what to do with her and was afraid the girl's parents would see her separated from her brothers and in the company of a strange man.

How could he explain it if he were confronted? He took her simply to keep from getting caught in his failed attempt to abduct her brother.

"He didn't want her. He wanted her older brother," Olmstead said. "If (he kidnapper) had walked over and grabbed Rachael from the playground, then I know it wouldn't have been Bishop. He wasn't interested in girls. But that's not how it happened."

Rachael's brothers said the man was a light-complexioned black man. Olmstead said maybe they mistook Bishop's tan from his frequent trips to the desert for dark skin. Olmstead also said that in 1982, Bishop wore his hair in a quasi-Afro.

And Bishop was also quite familiar with the Sunset area where Rachael was abducted.

Olmstead still holds out hope that Bishop will "come out with it" in a last-minute confession to a trusted confidant or in a letter.

Box Elder County Sheriff Robert Limb is not 100 percent convinced Bishop is a suspect in an unsolved 1983 killing there. But he's not ruling him out, either.

Bishop remains a suspect in the June 24, 1983, disappearance of Thomas J. Walling, a 9-year-old boy who ran away from a foster home and was later found floating in the Malad River.

"I was at one time fully satisfied that Bishop did it," said Limb, who has interviewed Bishop twice about the killing. "At one time I was 90 percent certain of it."

Now, Limb is less certain, "maybe 50-50."

The time frame of the Walling murder fits perfectly with the June 1983 Troy Ward murder and the July 1983 Graeme Cunningham murder, both of them victims of Bishop.

And there was circumstantial physical evidence linking Bishop to the scene of the Walling murder.

In addition, Walling was murdered in the same manner - beaten on the head with a blunt object - as were Ward, Cunningham and Daniels, and his body was disposed of in a river, as were the bodies of Bishop's other two 1983 victims.

Both Limb and Olmstead remain open-minded about their unsolved cases, and they are careful not to rule out other suspects.

"We are still getting leads on the (alling) case," said Limb, "and we probably spend one or two days a month investigating the case. We don't want to close it out or quit on it. It could be anybody."

Olmstead agrees, but feels a growing sense of frustration.

"We can't stop investigating the (unyan) case, and we won't," he said. "Maybe it wasn't him (Bishop), but it will always be in the back of my mind that he took it to the grave with him. Maybe it's selfish, but I don't want to chase false leads forever. I want this case over with."

Olmstead continues to investigate a lot of leads in the Runyan case. "We've got some new leads we're working on now," he said. He used to get excited every time someone would call with information. But six years of disappointment have tempered his enthusiasm.

"Despite the excitement and dejection, you just keep pushing. I'm going to keep working this thing until it's solved."