Officials now believe that one of the missing hikers found dead in Joshua Tree National Park shot and killed the other before turning the gun on himself, a representative of the San Bernardino County Sheriff’s Department said on Friday, Oct. 20, but evidence at the scene leaves much doubt as to a motive.

The couple had been battling the elements: The bodies were under a tree, with articles of clothing covering their legs to protect them from the sun, officials said.

They appeared to have been rationing food and had no water.

Authorities on Friday officially identified the hikers whose bodies were found Sunday afternoon in a remote part of the park as Joseph Orbeso, 21, of Lakewood and Rachel Nguyen, 20, of Westminster, who went missing in late July. A handgun recovered at the scene was registered to Orbeso, officials said.

“Based on evidence located at the scene, detectives believe Orbeso shot Nguyen, then shot himself,” a sheriff’s statement says. “The investigation into Orbeso’s actions remain under investigation.”

His motive may never be known.

Related: Hikers’ bodies found embracing in Joshua Tree shows son’s kindness, father says

“There is nothing left behind to give the investigators or the family any indication of why this happened,” said Cindy Bachman, a Sheriff’s Department spokeswoman in a telephone interview.

“There was nothing like a note or a phone call to explain the circumstances that we found,” she said. “It’s unfortunate because it leaves questions for their family.”

A statement from Nguyen’s family said the situation has been “very difficult for the family.”

“It was explained to us by the investigators on scene, with the circumstances and positioning of the bodies, that they believe this was a sympathetic murder-suicide. We hold no grudges against Joseph or the Orbeso Family.

“We extend our heartfelt condolences to the Orbeso Family, and that they will remain in our prayers.

“We thank God that we’ll be able to give Rachel a proper burial and lay her to rest,” the statement said.

Austin Young, 23, who lives in Lakewood and was Orbeso’s best friend, doesn’t believe Orbeso murdered Nguyen, a friend he had once dated.

“That is not the kind of person Joseph is,” Young said. “I think he brought a gun out there to protect Rachel. I think they got lost and were suffering in 100-degree heat.

“They had a choice of a slow and painful death or a quick death,” he said. “And they made the choice of a quick death. Joseph wouldn’t do it (the shooting) unless Rachel said she couldn’t take it anymore. I don’t want Joseph to go down as a murderer.”

Orbeso may have had the gun because he was employed as a security guard at a Long Beach golf course, Young said.

Orbeso and Nguyen had dated but most recently were friends, Young said. Orbeso was familiar with Joshua Tree National Park and had taken Nguyen there to celebrate her birthday, he added.

“He saw her socially and wasn’t going to push the relationship,” Young said. “He just wanted to do thoughtful things for her. He was never aggressive. He was the most respectful man I know.”

The bodies of Orbeso and Nguyen were found Sunday afternoon in a steep canyon to the far north of the Maze Loop Trailhead by Joshua Tree Search & Rescue members, who were accompanied by Gilbert Orbeso, Joseph’s father. The area where they were found is inaccessible by vehicle, according to sheriff’s officials.

Once they arrived by helicopter, deputies from the sheriff’s Morongo Basin Station found visible injuries to the bodies. The Homicide Detail was called in to take over the investigation, officials said.

After the remains were taken to the San Bernardino Coroner’s Office, an autopsy determined the injuries to be gunshot wounds.

Investigators and searchers have no indication that Orbeso may have been planning to hurt Nguyen, Bachman said.

“I’m not aware of anyone coming forward to offer information that Rachel was in any danger or that there was anything planned to cause harm to her,” she said.

It had been previously reported the pair was embracing when they were found Sunday. “It did appear that way, but we’ll really never know,” Bachman said on Friday.

Related: Friends, family believe bodies found in Joshua Tree to be those of missing Lakewood, Westminster hikers

Because of the condition of the bodies, sheriff’s officials said it would be difficult to determine exactly when the two died, whether it was soon after they were reported missing, or a few days or weeks after that.

“I want Joseph to be remembered as a kind, caring and thoughtful person,” Gilbert Orbeso wrote in an email to Southern California News Group soon after the two bodies were found and before authorities released information about the way they died.

“The way he was found beside Rachel holding her as they were seeking shade under the brush says everything you need to know about him as a man and as a human being,” he said. “I am proud to be his father and his kindness will live on in me and those who knew him best.”

The pair was reported missing on July 28 after the owner of a bed and breakfast in the Morongo Basin area where the two were staying called deputies to report Nguyen and Orbeso possibly went hiking in the Joshua Tree National Park that morning but had not returned.

Related: 2 bodies found in Joshua Tree National Park

Later the same day, Joshua Tree National Park Service rangers found their vehicle near a trailhead in the park. The Park Service immediately began a search.

The following day, July 29, the rangers asked the Sheriff’s Department for help. More than 250 search and rescue members — some volunteers — converged on the park for the next nine days. More than 10 search personnel were injured while looking for Nguyen and Orbeso, sheriff’s officials said. In total, searchers donated more than 2,100 hours during the attempts to locate the missing couple.

Beginning Aug. 6, the searches were scaled back to smaller teams on the weekend after authorities evaluated the “continuing risk to personnel vs. the reward of finding the couple alive,” a statement said.

Orbeso’s father was frequently part of those weekend search parties.

“Joshua Tree National Park is over 800,000 acres,” the Search & Rescue team said on its Facebook page on Thursday. “We are still unsure what happened. In general, it is surprisingly easy to get lost. …

“You can take a short hike and lose sight of the road, and, if you didn’t pay attention to what the landmarks look like, in the opposite direction, you could start wandering.”

Young said he hopes authorities will do a thorough investigation into Orbeso’s and Nguyen’s deaths: “I hope they find the truth,” he said.

The Nguyen family statement continued:

“Again, we’re humbled and grateful for the outpouring of love and support from the public. We cannot thank enough the folks from Joshua Tree Search and Rescue, San Bernardino Sheriffs, USMS, volunteers, and all the agencies involved in the search efforts.

“We also thank all of our family and friends for their prayers.”

Anyone with further information is asked to call Detective Scott Stafford or Sgt. Robert Warrick at 909-387-3589. Anonymous tips can also be left at 1-800-78-27463 or www.wetip.com.

Staff writers Keith Sharon and Sarah Batcha contributed to this report.