But the visit was anything but a normal trip to the park.
Inside the U-Haul was a collection of guns her ex had stolen after he and an accomplice allegedly killed and robbed former Brigham Young University professor Kay Mortensen, Bingham testified in 4th District Court on Wednesday during the first day of a jury trial for Bond, who is charged with aggravated murder and other felonies related to Mortensen's death.
Bond wanted to move the guns from where he and his accomplice, Benjamin David Rettig, had buried them in the desert near Vernal after the November 2009 burglary-turned-homicide at Mortensen's Payson Canyon home, Bingham said.
So Bingham sat with their son, while Bond re-buried the guns in a wooded area near the park.
Bingham said Bond told her shortly after Mortensen's death that he was involved, but he had insisted Rettig was the one who killed the retired engineering professor.
On the stand, Bingham burst into tears and covered her face when asked what her ex-husband had told her about that night.
"He said that him and his friend Ben drove up to Payson to Kay Mortensen's, which he knew from childhood," she said. "And that he entered Kay's home and took his life and took Kay's guns."
But it wasn't until Dec. 5, 2010, that Bingham told police about her ex-husband's alleged part in Mortensen's murder. She had told a friend, Peter Smith, about the crime, and Smith informed her that Mortenson's son and daughter-in-law had been charged with the murder and were slated to go to trial for the slaying.
So she went to police.
Her tip led police to the park where Bond had allegedly buried the guns months earlier, Utah County Sheriff's Detective Zach Adams said. Adams testified that deputies also found guns at Bond's home, and one was identified through a serial number as belonging to Mortensen. The serial numbers on the other guns had been scratched off, Adams said.
Pamela Mortensen Kay Mortensen's daughter-in-law testified Wednesday about the terror of stumbling into the middle of the crime occurring at her father-in-law's home.
Pamela Mortensen and her husband, Roger, knocked on the door to deliver a pecan pie on Nov. 16, 2009.
She said they were greeted by Bond and Rettig two men she assumed were there to fix the Internet at the Mortensen's home.
"They didn't have ski masks on," she testified. "They didn't look like anything scary. They just looked like regular people."
But Bond pulled a handgun, and with Rettig's help, used zip ties to bind the couple's hands.
"It was a very scary situation, Pamela Mortensen testified. "I didn't know if I was going to make it out of that house that night."
The men asked for their cellphones and IDs, and told the couple that they would live, but only if they told police the robbery had been committed by three black men.
Seventy-year-old Kay Mortensen who recognized Bond and let him into his home, according to prosecutors was apparently already dead when his son and daughter-in-law arrived.
Bond later told police that Rettig slit the victim's throat after bending him over a bathtub, and also stabbed him in the back of the neck, making "a statement related to a gladiator," according to jail documents. Rettig, however, told police it was Bond who cut Mortensen's throat.
Bond and Rettig left with 32 guns belonging to the victim.
Police initially did not believe the story told by Roger and Pamela Mortensen.
The couple were arrested and charged with the murder and spent five months in jail before Bingham tipped police to Bond and Rettig.
Deputy Utah County Attorney Tim Taylor told the jury in his opening statement that prosecutors had originally charged the wrong people, saying a very unusual and clean crime scene, along with inconsistent statements from the couple, were to blame.
"This has been a long time coming," Taylor said. "We arrested the wrong people. We accused the wrong people. We made a mistake. I admit that to you. We take absolutely full responsibility for that. What I want you to focus on [is] we got it right this time. No doubt about it. We got it right."
Smith, who went with Bingham to the police station with information about Bond, testified that he first met Bond through a mutual friend in March 2010. They hung out together on several occasions, he said, and their "friendly banter" would often turn to guns, knives, and how to disarm a person. On more than one occasion, the conversation turned to murder, Smith said.
"He would talk about slicing throats," he said. "That that's how he would do it. Slicing throats."
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.
Howard said Bond's father knew Mortensen through Payson's Community Emergency Response Team (CERT) program. And Bond knew the professor while he was a teenager, Howard said, but then left Payson when he joined the U.S. Air Force after graduating high school. When Bond was honorably discharged, Howard said that he went to Utah State University in Logan, where he was a full-time student and cared for his young son.
On the weekend before the murder, Howard told the jury that Bond had gone to Rettig's home in Vernal, where they spent the weekend hanging out, playing video games and talking.
At some point, their talk turned to emergency preparedness and gun ownership, Howard said, and Bond brought up an old friend in Payson who had an extensive gun collection.
"This had planted the seed of an idea in Benjamin Rettig's mind," Howard said.
Rettig, 25, pleaded guilty in June 2011 to aggravated murder and aggravated kidnapping. In exchange, prosecutors agreed to not seek the death penalty and to drop two counts of aggravated kidnapping and one count of aggravated burglary. As part of the plea deal, Rettig who is serving 25 years to life in prison also agreed to testify against Bond.
The death penalty also has been taken off the table for Bond, 25, after a partial resolution was reached in November. If found guilty of aggravated murder, Bond will be sentenced to life without the possibility of parole.
Bond also is charged with three counts of aggravated kidnapping, aggravated burglary and aggravated robbery.
Twitter: @jm_miller Bond's former associate agrees to testify
Benjamin Rettig, 25, pleaded guilty in June 2011 to aggravated murder and a count of aggravated kidnapping. In exchange, prosecutors agreed to not seek the death penalty, and to drop two counts of aggravated kidnapping and a count of aggravated burglary. Rettig, who is serving 25 years to life in prison, also agreed as part of the plea deal to testify against Martin Bond, whose jury trial began Wednesday.