The disappearance of 78-year-old political activist Surachai Danwattananusorn, also known as Surachai Saedan, and the killing of his two close aides, who had been living in exile in Laos, need not go down in history as unsolved and unexplained mysteries.
Whether they are classified as enforced disappearances or appallingly brutal and seemingly extrajudicial murders, this should not become the new normal for political activists fleeing prosecution at home to Laos or Cambodia.
Both the Thai and Lao governments need to come up with an explanation for what transpired in these cases.
Just a few days before the 2014 coup, Surachai fled to Laos to avoid the threat of arrest over lese majeste offences. His two aides, Chatchan Bupphawan and Kraidej Luelert, followed him. They later criticised the regime and the high institution on online radio programmes. The last time they were seen was on Dec 11 in Vientiane.
Later that month two dead bodies were found in the Mekong River, in Thailand's Nakhon Phanom province. After running DNA tests, the police this week confirmed their identities to be Chatchan and Kraidej.
While the cause of their deaths has yet to be determined, the details of the case are quite gruesome. Both men were disembowelled and their stomachs stuffed with concrete blocks, presumably to weigh them down. Their bodies were then wrapped in hemp sacks and a fishing net and dumped in the river.
Meanwhile, Surachai still ranks as a missing person. Even though there is an unofficial account of a third corpse being found, and then having been lost somehow in the running waters of the river, his wife does not believe it is the body of her husband.
The Thai army claims it has no knowledge about what happened to the two dead activists prior to their death, and insists it was not involved in any way in their disappearance.
But that does not free either the Thai security authorities or the government from their dutiful responsibility to investigate this case and unearth the truth behind the killing, as well as finding out if Surachai is still alive or has also become a victim of enforced disappearance.
Given the their provocative activism against the military, some suspect their disappearance and, for the two aides at least, subsequent murder may have been orchestrated by elements within, or affiliated with, Thailand's security forces. At present, this is nothing but a rumour and speculation.
If the government and army believe such a theory to be groundless, they must call for a thorough and credible investigation. The regime should also reach out to its Lao counterpart for help with the probe. Numerous CCTV cameras have been installed on Vientiane's streets, so it's possible one or more could offer a clue.
Both governments can work together using the cooperation mechanism they agreed to in December 2017 to help locate people seen as security threats.
However, this cooperation has also made them subject to rumours that they could have colluded in the deaths.
Previously, two other Thai activists went missing while living in exile in Vientiane: Itthipol Sukpaen vanished in June 2016, and Wuthipong "Ko Tee" Kochathamakun disappeared from his residence in July 2017. Eyewitnesses said he was abducted by a group of Thai-speaking men dressed in black.
That they were suspects in a lese majeste case does not excuse the Thai government from offering them reasonable protection and justice.