The parents of Perth brothers Jake and Callum Robinson say the loss of their fun-loving sons has made the world “a darker place” as they prepare to bring them home.

Debra and Martin Robinson flew to Mexico to identify the bodies of their sons after their decomposed remains were found at the bottom of a 15-metre well, each with a single gunshot wound to the head.

Breaking their silence, the couple spoke to journalists, including from Nine News, on Wednesday (AEST) from a beach in San Diego, US, where Callum had been living and building a life for himself.

His little brother Jake was visiting when the pair embarked on their surfing and camping adventure just over the border in Mexico’s Baja California surfing mecca.

“Our hearts are broken and the world has become a darker place for us,” said Debra as she choked back tears and was comforted by her husband.

“We also mourn the loss of Carter Rhoad, a close friend. They were young men enjoying their passion of surfing together.

“Now it’s time to bring them home to family and friends and the ocean waves in Australia.”

“Please live bigger, shine brighter and love harder in their memory.”

Perth siblings Jake and Callum Robinson, both in their 30s, went missing on their surfing trip.

The parents wanted to thank those who had contacted them to offer support, and said they were proud of their sons and their life choices.

“Callum was a lovable, larger-than-life character and considered the United States his second home,” she said.

“Known as the Big Koala, he played professional lacrosse in the PLL and represented Australia in the World Championships.

“His brother Jake was a happy, gentle and compassionate soul who was pursuing a career in medicine.

“Jake’s passion was surfing and it was no coincidence that many of his hospitals that he worked in were close to surfing beaches.”

It’s been reported that one of the first people to be charged will face court on Thursday (AEST). The charges are expected to be upgraded to murder.

Debra and Martin Robinson will bring their boys home. Photo: Instagram

How beach trip turned deadly

The two Australians and their American friend had been doing what they loved on the stunning, largely isolated stretch of Baja California’s Pacific coast.

Their last images on social media showed them sitting and gazing at the waves, contemplating the breaks.

What happened to end their lives may have been as random as a passing ute full of people with ill intent. The surfers were shot in the head, their bodies dumped in a covered well kilometres away. How it unfolded was the stuff of nightmares.

The trio had apparently stopped to surf the breaks between Punta San José, about 80 kilometres south of Ensenada, and La Bocana, further north on the coast. They were attacked there on April 28 or 29.

As soon as police arrived at their last known campsite, it was clear that something had gone violently wrong.

There were bloodstains and marks “as if heavy objects had been dragged”, leading to suspicions of an attack, the Baja California state prosecutor’s office said in an attempt to reconstruct the scene.

Chief state prosecutor María Elena Andrade Ramírez said on Sunday that the killers apparently drove by, saw the foreigners’ vehicle and wanted to steal its tyres and other parts.

Such was the banality of evil, she said, that “they were not attacked because they were tourists. … The evidence suggests they (the killers) did not know where they were from.”

The foreigners surely resisted, she said. “These people, the assailants, took out a gun, and first they killed the one who was putting up resistance against the vehicle theft, and then the other two came along and joined the fight to defend their property and their companion who had been attacked, and they killed them too.”

The brothers shared a passion for surfing. Photo: Supplied

Andrade Ramírez said the reconstruction of events was based on the forensic examiner’s reports, noting all three had bullet wounds to their heads.

There was a hurried attempt to destroy evidence. The foreigners’ tents were apparently burned. Their Chevrolet Colorado was driven kilometres away and burned. The assailants’ truck was later found with a gun inside.

Then, at “a site that is extremely hard to get to”, the bodies were dumped into a well about six kilometres away. Investigators were surprised when, underneath the bodies of the three foreigners, a fourth body was found that had been there much longer.

“They had to have previous knowledge of it,” Andrade Ramírez said of the attackers, acknowledging the possibility they were behind the previous killing.

The well had been covered with boards.

“It was literally almost impossible to find it,” Andrade Ramírez said.

It took two hours to winch the bodies out.

Investigators searched the cliffs of La Bocana. Photo: AAP

Prosecutors have said they are questioning three people in the killings. Two were caught with methamphetamine.

One of them, a woman, had one of the victims’ mobile phones when she was caught. Prosecutors said the two were being held pending drug charges but remained suspects in the killings.

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

The third man was believed to have directly participated in the killings. In keeping with Mexican law, prosecutors identified him by his first name, Jesús Gerardo, alias “el Kekas”, a slang word that means quesadillas, or cheese tortillas.

Three suspects have been arrested. Photo: Supplied

Andrade Ramírez said he had a criminal record that included drug dealing, vehicle theft and domestic violence, adding, “we are certain that more people were involved.”

She emphasised that she could not discuss anything related to the suspects, or their possible statements, because that was not allowed under Mexican law and might prejudice the case against them.

Andrade Ramírez noted that the victims’ families said the brothers and Rhoad had come many times to the seaside spot and never had any problem. This time, however, “there was no way to ask for help when the attackers showed up”.

-with AAP