The mother of two Australian surfers killed in Mexico delivered a moving tribute to her sons Tuesday at a beach in San Diego.

“Our hearts are broken and the world has become a darker place for us,” Debra Robinson said, fighting back tears. “They were young men enjoying their passion of surfing together.”

Her sons, Callum and Jake, were allegedly killed by car thieves in Baja California, across the border from San Diego, somewhere around 28 or 29 April.

Ms Robinson also mourned the American who was killed with them, Jack Carter Rhoad.

The beachside location where she spoke, across the border from the Baja California city of Tijuana, was no coincidence. She noted that her son Callum “considered the United States his second home”.

Robinson noted that her son Jake loved surfing so much that, as a doctor, he liked to work in hospitals near the beach.

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

Choking back tears, Ms Robinson conveyed a final message that coincided with her sons’ adventurous lifestyles.

“Live bigger, shine brighter, and love harder in their memory,” she said.

Ms Robinson thanked Australian officials and supporters there and in the United States.

While she thanked Mexico’s ambassador to Australia, she notably did not thank the local officials in Baja California who eventually found the bodies of her sons and Carter Rhoad.

Their killers dumped the bodies of the men into a well about 4m (6km) away from where they had been attacked at a beachside campsite. Investigators were surprised when, underneath the bodies of the three foreigners, a fourth body was found that had been there much longer, suggesting the gang had been working in the area for some time.

The fact that such killers are not caught or stopped in the overwhelming majority of cases in Mexico suggests that authorities allow killers to roam free and only investigate such disappearances when they are high-profile cases involving foreigners.

Ms Robinson said that her sons’ bodies, or their ashes, will eventually be taken back to Australia.

“Now it’s time to bring them home to families and friends,” she said. “And the ocean waits in Australia.”

Prosecutors have identified three people as potential suspects, two of whom were caught with methamphetamines. One of them, a woman, had one of the victims’ cellphones when she was caught. Prosecutors said the two were being held pending drug charges but continue to be 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 when or 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-filled tortillas.

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.”

Australian Prime Minister Anthony Albanese said on Tuesday he had requested an opportunity to speak to Robinson and her husband Martin.

“This is a terrible tragedy and my heart goes out to them,” Albanese told reporters in the Queensland state town of Rockhampton.

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.