A Utah mom will not be charged after she left a loaded handgun on a diaper-changing table in a restroom near a children's play area at the Loveland Living Planet Aquarium.

The woman didn't knowingly abandon her gun in the restroom, prosecutors wrote in a letter to Draper police, so they couldn't build a case for reckless endangerment.

In the letter, Salt Lake County prosecutors wrote that the woman had called Draper police in search of the missing gun July 10, the day that visitors had found it in a restroom next to the aquarium's Tuki's Island indoor playground.

Aquarium staffers have said there is a posted no-weapons policy, but the woman brought the gun in a holster and took it off in the restroom.

(Erin Alberty, The Salt Lake Tribune) This sign shows no weapons are allowed at the Loveland Living Planet Aquarium in Draper.

"[She] told police that she had to use the restroom and she was chasing her children around the restroom and accidentally forgot about the firearm," prosecutors wrote. "[She] said that both her children crawled under the bathroom stall and ran off. [She] said she hurriedly dressed herself and ran after her children and forgot about the gun."

The gun was inside a holster and was loaded with six bullets when an aquarium visitor found it, prosecutors wrote.

"One round was in the firing chamber and the safety was off," prosecutors wrote.

But to prove reckless endangerment, the charge they were considering, prosecutors wrote that they would have to prove the woman knew leaving her gun in the restroom could lead to someone getting hurt or killed but "consciously disregarded that risk and went ahead anyway."

"It is not enough to prove that [she] ought to have been aware of the risk,” prosecutors wrote. “Utah law requires us to show [she] was aware of the risk but left her gun in the restroom anyway.”

It would be different, Salt Lake County District Attorney Sim Gill noted, if the woman had said she left the gun in the restroom thinking, "I'm going to leave it here; it'll be fine."

"The mental state of that versus 'I just put this to the side because I'm trying to chase a baby and then the other kids take off.' ... It doesn't meet the mens rea" — the law's standard for intent, Gill explained. "It was not an easy decision. [Screening prosecutors] kept going back and forth."

In this case, no one was injured. But what if someone had been shot by a gun that was left unattended with a round in the chamber and the safety off in or near a children's attraction with a posted no-firearms policy?

Absent proof that the gun owner knowingly handled the gun in a way that is risky, Gill said, reckless endangerment still doesn't apply.”

"Is there a gap there? Yes, there is," the district attorney said. "Is there a violation available that's a class A [misdemeanor] or higher offense level? No. That's the problem."

(Rick Egan | The Salt Lake Tribune) Sim Gill, Salt Lake County district attorney. March 9, 2018.

Gill said his office will forward the case to Draper prosecutors to review lower charges — potentially trespassing, given the aquarium's posted ban on guns. Utah’s concealed carry permits do not extend to “any secured area in which firearms are prohibited and notice posted,” according to the Utah Department of Public Safety, but concealed guns are allowed in public schools, for example.

Meanwhile, Gill said, the case shows that Utah's gun laws may not account for the responsibilities of ownership. He acknowledged that many Utahns may believe that if a parent cannot secure a gun while taking care of excited young children at a family attraction, bringing the weapon in the first place is reckless.

"Most citizens are going to think of it as being negligent," said Gill, noting that he is a concealed carry permit holder and often in possession of a gun.

"If you're leaving unattended firearms, that accountability ought to be more immediate. To me that has nothing to do with the right to possess a gun; it has everything to do with the responsibility of carrying that gun around," Gill said. "I understand there are the challenges of daily life, but there is also the necessary urgency of responsibility for an item that's inherently dangerous. That expectation should have a level of accountability short of [reckless] behavior."

For example, Gill suggested, the Legislature could explore criminal violations to be attached to Utah's permit statutes.

“Can the law be created to say, ‘OK, if you’re a concealed carry person, you need to be responsible all the time for what you do [with the gun]?’ If it is not on your person and you leave it unattended, here is a category of offense. If there is a subsequent injury that occurs, here is a category of offense,” Gill said. “That would force people to look at their responsibility in different ways.”

Aquarium officials declined to comment Saturday.