He was due to take up a position at a hospital in Geelong, Victoria, on his return. He previously worked in regional hospitals around Australia.

On social media, Perth friend Jenny Nguy said Jake had a bright future ahead of him.

“I can’t stop thinking about you, your smile, your laugh, your kindness,” Nguy said. “I can’t stop crying thinking about how your parents are feeling right now.”

San Diego surf photographer Randy Dible expressed his sadness at the news, saying Callum had bought a print from him weeks ago and discussed his plans for a surfing trip to Baja California.

“I told him to go to La Bocana where there’s great fishing and a wave to surf ... I drew him a little map on a napkin,” he wrote. “Really great guy and champion lacrosse player and surfer,” he said. “Life is fleeting.”

Deadly trip to Mexico

The Australian brothers and their American friend, last seen on April 27, were found at the bottom of a 15-metre well near Santo Tomas – about 115 kilometres south of the US border – on Friday.

Chief state prosecutor Maria Elena Andrade Ramirez said the alleged killers drove by their campsite, saw their tents and ute, and wanted to steal their tyres.

“Surely they resisted,” she said of the victims. The thieves shot and killed them, she said.

The thieves then went to what she called “a site that is extremely hard to get to” and dumped the three men’s bodies into a well. She said investigators were not ruling out the possibility the same suspects had earlier dumped a fourth unrelated body that was found in the well.

She said police had earlier found evidence that led them to suspect the men had been attacked, including abandoned tents, a bullet casing and drag marks.

Baja California prosecutors said they were questioning three people, two of them because they were caught with methamphetamines. Prosecutors said the two were being held pending drug charges but continued to be suspects in the killing.

A third man was arrested on charges of a crime equivalent to kidnapping before the bodies were found. It was unclear if he would face more charges.

Mexican authorities believe the third suspect directly participated in the killings. In keeping with Mexican law, prosecutors identified him by his first names, Jesus Gerardo and the alias “el Kekas”, a slang word that means “quesadillas” or cheese tortillas. Andrade Ramirez said he had a criminal record, and that more people may have been involved.

Before providing an update on the case, Andrade Ramirez and her team met the victims’ families, the Australian ambassador to Mexico, other embassy officials and FBI staff.

Baja California is one of Mexico’s most violent states, although the Ensenada area is considered safer. The US State Department has advised Americans to reconsider travel to the state due to crime and kidnapping.

In 2015, two Australian surfers, Adam Coleman and Dean Lucas, were killed in western Sinaloa state, across the Gulf of California – also known as the Sea of Cortez – from the Baja peninsula. Authorities said they were victims of highway bandits. Three suspects were arrested in that case.