The parading of criminal suspects at press conferences and getting them to stage re-enactments by the police are needless as per procedural law and are a human rights violation, a senior Lawyers Council of Thailand official said.
Jessada Anujaree also said that making self-confessed murderers apologise to relatives of victims usually involved reluctant relatives.
He said re-enactments were needless because only testimony, examinations and evidence were crucial in trials for judges to acquit or convict defendants.
"Police do it to over-convince the judges to make sure that their [the suspect's] confession during the police investigation would not be altered during testimony, because it is impossible that anyone accused of a crime would apologise publicly if he or she had not committed the crime," he said.
Jessada said some suspect might have been forced to offer apologies, and frequently suspects got bashed by angry relatives or mobs.
This was a clear violation of a suspect's basic right to be protected when in police custody.
The familiar scenario was discussed widely and criticised heavily when four suspects accused of firing M79 grenades during the political unrest were ordered by police during a recent press conference to kneel before the parents of two young children killed when grenades were fired into a political rally site earlier this year.
A member of the National Human Rights Commission, Parinya Sirisarakarn, agreed that making suspects apologise to relatives of victims violated their human rights because they had not been convicted by court yet and the NHRC had continuously urged police to stop the practice.
But a senior policeman, who asked not to be named, said suspects "sometimes" initiated offers of apologies to relatives.
He said these suspects had mostly committed violent crimes against young victims and were highly remorseful.
"Making apologies will not affect verdicts or do favours in their trials, nor will it undo their criminal liability," he said.
It is believed the practice has led to wrongful convictions and imprisonment.
Among many infamous such incidents is the Sherry Ann Duncan murder case in 1986.
The five suspects were arrested and later taken to the family of the 16-year-old victim to apologise while the police earned applause for their perceived efficiency in making quick arrests.
But all fives were eventually acquitted, some posthumously, due to the flawed police investigation. One of the five accused died in custody, another one contracted pneumonia in prison and died five months after being released and another died of cancer not long afterwards.
The only survivor is barely able to walk after sustaining a spinal injury in a prison attack.
During his wrongful sentence, his wife reportedly died of stress, one of his daughters was raped and killed and one of his sons went missing. The case was reopened in 1995, leading to the conviction of the real murderers.