Samong Traisattha, 36, the lead singer of the band Surrender of Divinity, was found stabbed to death in his home in Bangkok Wednesday night, the Bangkok Post reported.
The victims wife, Jaruvan Surapol, 34, told police that a fan of her husband's came to their home Wednesday to have some shirts screen-printed and to drink with Samong.
Later in the evening, Jaruvan said she went to check on her husband and found him in their living room in a pool of blood.
Jaruvan identified the suspect as Prakarn Harnphanbusakorn, police said.
On Friday, a Facebook user named "Maleficent Meditation," whom police believe to be Prakarn, wrote that he had killed Samong and posted pictures of the crime scene, the Post reported.
"I have intended to end my life since I was 25. Because I'll die eventually, I want to drag down those who tarnish Satanism with me. But I refrained from killing women and children," he wrote.
"In my view, I have more respect for devoted Buddhists, Christians and Muslims than those who call themselves Satanists without knowing anything about it," he wrote. "If I did not kill him, I'm sure he would be murdered by someone else later."
The Facebook user went on to say that he is not a fan of Surrender of Divinity and that he did not want people to associate Samong's murder with those of other famous people.
Police officers are still searching for Prakarn.