The four ex-teachers of Nong Khai’s Bung Khlong Lhong School – Bualoy Khlongdee, 58, Amkha Phutongjai, 56, Kwanpak Phokhong, 55, and Lamai Punriboon, 54 – met with deputy permanent secretary for the Justice Ministry Pol Colonel Dusadee Arayawuth yesterday.

Dusadee said the Department of Special Investigation (DSI) was already working on the case to provide them with justice.

The four testified in the murder trial of school director Chusak Sutthasri, who was eventually acquitted in 2014. The case centred on the fatal shooting of teacher Pethai Amatrattana during a party on March 3, 2009.

Police initially arrested and charged Chusak with murder after an alleged argument at a party where alcohol beverages were consumed.

The testimony of the four teachers contributed to Chusak’s acquittal.

However, the case investigator filed charges against the four teachers in 2013 for giving false information to authorities and destroying evidence and they were each sentenced to four years in jail in 2015.

They served only 22 months as their sentences were reduced by royal pardons until their release last December.

During their time in prison, the teachers tried to appeal their sentences but their petitions were turned down.

They are now seeking a retrial to prove their innocence, with the aim of being reinstated by the Education Ministry so they can return to teaching.

The four women attended the party at the school’s infirmary when Pethai, a music teacher, was shot dead. They later disposed of alcohol bottles and glasses out of fear of disciplinary punishment for drinking alcohol at a state office.

A request by the DSI for a retrial last November was turned down on the grounds that there was not any new evidence, a source at the ministry said yesterday.

The DSI probe, which lasted for more than a year, found that a gunman was hired by an unknown person to kill Chusak but instead shot Pethai by mistake, because he wore the same colour shirt and happened to sit in Chusak’s designated spot.

Bualoy said that during their time behind bars, they taught fellow inmates an informal curriculum until graduation, which entitled them to sentence reductions.

As the Justice Ministry has begun to assist them in their case, the Education Ministry – which initially fired them from the civil service due to the criminal convictions – has changed the order, which means they are now entitled to retirement pensions, Bualoy said.