Police are hesitating over whether to release CCTV footage allegedly showing the fatal shooting of a Lahu activist by a soldier in Chiang Mai two weeks ago.
Responding to mounting calls to release the footage, deputy police spokesman Krissana Pattanacharoen said investigators have a duty to compile all evidence before anything is revealed to the public. And if it is thought the footage may jeopardise inquiries, it cannot be released.
He insisted no one will interfere with the police investigation, adding that no directives have come from the army on how the case should be handled.
Chaiyapoom Pasae, who was president of the Northern Traditional Plant Preservation Network, was shot dead at a checkpoint in Chiang Mai's Chiang Dao district on March 17.
Authorities claim they found the young activist transporting methamphetamines at a security check.
He subsequently tried to flee and then attacked troops with a hand grenade, prompting one soldier to fire a single shot in self-defence, the army said.
But Chaiyapoom's death has raised questions about how the situation was handled.
Police will separate the case into three parts, Pol Col Krissana said.
The first concerns the drug allegations, the second Chaiyapoom's autopsy, and the third his shooting by a soldier, in what was the army has insisted was an act of duty.
National police chief Chakthip Chaijinda insisted police will proceed with the case without bias, adding the case is not complicated.
"Had the officer not shot him, he would have fired at the officer," said Pol Gen Chakthip.
Police Region 5 provincial commissioner Poolsap Prasertsak has reported Chaiyapoom had a background of drug offences, the police chief said.
Army chief Chalermchai Sittisat said the footage is only one piece of evidence involved in the case, and not conclusive.
He added that he would let the justice process take its course.
He said he had seen the footage, but it fails to bring about a conclusion to the case.
"The army's fact-finding committee has reported its initial findings," said Gen Chalermchai.
He said the report will stay with the army and will not be shared with police.
Meanwhile, the National Human Rights Commission (NHRC) has contacted the Justice Ministry's Rights and Liberties Protection Department to provide safety to witnesses in Chaiyapoom's case.
Pitikan Sithidej, the department chief, said the agency will examine whether witnesses are eligible for protection.