"He just said he wanted to see me," Rettig testified.
But when Deputy Utah County Attorney Tim Taylor asked what happened after Bond arrived at his Vernal apartment, Rettig took a long pause before refusing to answer the question.
"I know everyone ... it was in the agreement to, and everyone expects me to, but I would feel more comfortable stopping right now," he said.
Rettig's refusal to answer questions temporarily halted proceedings on the second day of Bond's trial, as attorneys argued Rettig's legal rights, including whether an appeal filed by Rettig's attorney asking to withdraw his guilty plea in connection with Mortensen's murder could affect his right against self-incrimination.
But Judge Thomas Low determined Rettig's appeal had been dismissed, and there was no reason he could not testify.
Finally, Low asked Rettig again if he would answer questions.
"I would just prefer not to testify," Rettig said.
"Are you willing to testify, or are you refusing?" Low asked once more.
"I'm refusing," Rettig said quietly.
Rettig who is serving 25 years to life in prison pleaded guilty in 2011 to aggravated murder and aggravated kidnapping for his part in Mortensen's slaying. In exchange, prosecutors agreed to not seek the death penalty and they dropped two counts of aggravated kidnapping and one count of aggravated burglary. As part of his plea deal, Rettig agreed to testify against Bond.
Taylor said outside of court that Rettig's refusal to testify doesn't void his plea deal, but the Utah County Attorney's Office will write to the Board of Pardons and Parole advising them that Rettig did not follow through. Rettig will not be in front of the parole board until at least 2036.
Taylor said that while it wasn't a huge blow to the case, he was disappointed Rettig chose not to testify, saying his office had met with him in prison, and that while Rettig seemed reluctant, he was still willing to testify.
"He agreed," Taylor said. "We were extremely disappointed. He had some very pertinent information."
Kay Mortensen's wife, Darla Mortensen, said she was also disappointed that Rettig did not honor his plea agreement, calling it a "big blow."
"I think it takes away a lot of the prosecutor's case," she said. "I'm concerned about what the outcome will be."
Much of the prosecution's remaining case now rests on a series of hand-written notes allegedly passed between Bond and a 21-year-old inmate at the Utah County jail in 2011.
The inmate testified Thursday that he and Bond passed the notes by "fishing" tying a note to a shoestring and tossing it between cells.
A Utah County jail staff member testified that the two had stayed in nearby cells, and a handwriting expert with the Salt Lake County Police Department verified that the notes were in Bond's handwriting. The notes were not published to the jury on Thursday, but Taylor told reporters outside the courtroom that the pieces of paper contain an alleged confession by Bond that he was the one who killed Mortensen.
Taylor said the notes will be shown to the jury Friday, and will likely be read aloud in court at that time.
"[The inmate] is asking Bond why he's blaming Rettig," Taylor explained outside the courtroom. "Bond, in the notes, says, I'm the one who killed Kay [Mortensen], but Ben made me."
The inmate, who is now in the Utah State Prison after being convicted of robbing a credit union, used the notes from Bond as leverage to get a better plea deal in his robbery case. He also agreed to testify at Bond's trial as part of his deal.
From the start of the case, Rettig and Bond have blamed each other for actually killing the 70-year-old former engineering professor by cutting his throat at his Payson Canyon home.
Defense attorney Stephen Howard told the jury it was Rettig's idea to rob Mortensen, and that Bond reluctantly agreed, but said they would only steal the guns if no one was home.
Mortensen's son and daughter-in-law, Roger and Pamela Mortensen, were originally charged with the slaying, and they spent five months in jail before Bond's former wife went to the police with information about his alleged involvement.
Guns owned by the victim were later found where Bond allegedly buried them near Vernal.
Bond's trial, slated to go through next week, is moving quicker than expected. Depending on the number of witnesses called by the defense, the jury could start deliberating as early as Friday afternoon.
If found guilty of aggravated murder, Bond, 25, will be sentenced to life without the possibility of parole. He also is charged with three counts of aggravated kidnapping, aggravated burglary and aggravated robbery.