five of 9 judges to rule on both Yingluck, Boonsong cases

The judges – Cheep Julamon, Wiroon Sangtian, Slaikate Wattanapan, Thanarirk Nitiseranee, and Pison Pirun – will help make a final decision in both Yingluck and Boonsong’s cases. Cheep, Thanarirk and Pison were on the panel that heard the case over the deadly crackdown on yellow shirts against former prime minister Somchai Wongsawat from the Pheu Thai Party, who is a brother-in-law of controversial former prime minister Thaksin Shinawatra. The trio were among the majority of judges who acquitted Somchai and other defendants in the case.
Thanit Ketsawapitak, a senior judge sitting in the panel judging Yingluck’s case, was also a member of the judges’ panel that ruled in 2010 to confiscate Bt46 billion of Thaksin’s assets, for benefiting from corrupt dealings while he was prime minister.

Prior to that, Thanit had also voted to dissolve the Thai Rak Thai Party in May 2007, after the coup in September 2006 that ousted Thaksin’s government. Thanit, however, was among the minority of judges to vote against the imposition of a five-year political ban on Thaksin as a consequence of the ruling. 
He was also a member of the panel that heard Pheu Thai’s ex-deputy interior minister Pracha Maleenont’s malfeasance case in connection with the fire vehicle scandal.
Slaikate and Ubonrat Luiwikkai were on the panel ruling on Surapong Suebwonglee, a former information and communications technology minister, who was found guilty of dereliction of duty and malfeasance for changes involving a concession contract. The amendments enabled Shin Corp, then owned by the Shinawatra family, to reduce its shareholding in Shin Satellite from 51 per cent to 40 per cent. He served 10 months in jail and was released earlier this year. 
There have been changes in the panels. Two judges, Veerapol Tungsuwan and Sirichai Watanayothin, were selected in 2015 to rule on both cases, but Veerapol was then promoted to Supreme Court president and Sirichai Wattanayothin resigned from his post after failing to win a nomination to head the Supreme Court. 
They were replaced by Pison and Sophon Rojanon. The latter was also on the panel ruling in the case against former PM Somchai and voted that he was not guilty.
Another judge in the panel, Thanasit Nilkamhaeng, also sat on the ruling panel that heard Somchai’s case.
All members of the ruling panels are senior judges at the Supreme Court and most are presidents of the court’s divisions and vice president of the court. In order to be assigned a seat on the panels, judges would have been supported by all Supreme Court judges.