Matt and Hamish Day were arrested in March.
Thailand was the first Southeast Asian country to free up medicinal use in 2018.
The suspected shooter had been receiving psychiatric treatment but had skipped his prescribed medicine on the day of the shooting.
Daniel Sancho Bronchal is accused of dumping plastic bags containing body parts of a man at seven sites on the tourist island of Koh Phangan.
"Pai Lin's back still bears scars from old pressure points"
The boat was knocked over by four-metre waves and strong winds, which has seen six people die.
The fire broke out at a nightclub in Thailand's Chonburi province
Rescuers had to do CPR to save the older elephant.
While officials did not link the two incidents directly, the violence came weeks after the government reopened a dialogue with insurgents from a Malay-Muslim minority.
