A Utah man who admitted to killing his girlfriend and her 3-year-old son will not be allowed to seek a lower sentence in exchange for helping police find their bodies, a judge ruled on Tuesday.

Christopher Poulson has pleaded guilty to first-degree felony murder and second-degree felony manslaughter in the 2015 deaths of 23-year-old Emily Quijano and her 3-year-old son, Gabriel Almiron. But prosecutors agreed to support reduced charges if Poulson could help lead investigators to Quijano and Almiron’s bodies.

Christopher Poulson

Based in part on Poulson’s recollections, search teams on Sept. 6 found the bodies of Quijano and Almiron buried in a shallow grave near a tree about 5 miles south of Eureka in Juab County.

But a Utah County judge will not allow Poulson to withdraw his original guilty plea and plead instead to 20 second-degree felonies. The new charges would have reduced his maximum sentence from life in prison to no more than 30 years.

“If I were to agree to this, I’d be limiting the Board of Pardons ... to 30 years, and I’m just not willing to do this at this time,” said 4th District Judge Robert C. Lunnen. “... It’s difficult for me as a court to accept a 30-year limit on two very important lives.”

Prosecutors said Quijano and Almiron’s family agreed to the deal in order to secure information that might help them recover the victims’ bodies.

“While I won’t say they were 100% unanimous in their full support of this plea, they were in large part in support of it,” said Deputy Utah County Attorney Lance Bastian. “At the end of the day, everyone agreed to it.

Quijano’s mother, specifically, wanted the state to follow through on the agreement with Poulson.

“Not only did she feel like this was appropriate, this was fair — but she felt very strongly this is what she would want to happen," Bastian told Lunnen. The mother deeply wanted the remains of her daughter and grandson to be recovered. When that finally happened, she believed it was providence — not only that the bodies were found, but also that Poulson receive the benefit that the family had agreed to, Bastian explained in an interview.

“This has been big for them, to find the bodies, to be able to lay them to rest in a respectful way,” Bastian said.

Poulson said he injured Almiron while he was babysitting the child on Sept. 8, 2015. He put Almiron to bed, and Quijano returned and went to sleep.

When Poulson woke up the next morning, he found that Gabriel had died overnight. He panicked and shot Quijano while she slept, prosecutors have said.

Defense attorneys had Poulson review maps and video they had filmed of the area where he thought he had buried the remains, but Poulson struggled to recall the exact spot, said Matthew Morrise, Poulson’s attorney.

For weeks, investigators and volunteers searched. A volunteer from Juab County eventually noticed a tree that resembled one that Poulson had described, Bastian said. He began to dig and quickly found Quijano and Almiron’s remains, Bastian said. Medical examiners confirmed that Quijano had been fatally shot, but could not conclusive determine how Almiron died; he had not suffered a skull fracture, Bastian said.

The family later paid respects at the scene, Bastian said.

The agreement between Poulson and prosecutors to request reduced charges even after he had entered a guilty plea was highly unusual, Bastian acknowledged.

“I’m not aware of [another such case],” Bastian said.

He said he was not worried that Lunnen’s denial would make future defendants less likely to trust prosecutors in plea negotiations.

“Usually before we have an agreement like this, [we] go to the judge,” Bastian said. “Judge Lunnen made it very clear he was not agreeing upfront” to a change in charges.

“This one’s a little different,” Lunnen said. “Most often, when counsel have a joint agreement, I’ll usually follow that agreement.”

Poulson is scheduled to be sentenced Sept. 26.