Chaimongkol Jaiboon-upatam, 38, allegedly committed the robbery on September 27. Police traced him to the Mor Chit terminal where security cameras recorded him taking a bus to Loei province.
Chaimongkol was arrested in Loei province while his Laotian wife Chanda Chanchok, 24, who usually helped him escape, was arrested in Nong Khai province.
On September 27, Chanda was sent to plant evidence near the shop to confuse police before Chaimongkol's alleged heist.
They left the gold with their friend Suriya in Nakhon Pathom province and met again at the Mor Chit terminal before separating to hide themselves. Suriya was later arrested.
Chaimongkol also allegedly robbed a gold shop in Khon Kaen province on July 26, 2019, taking away Bt7-million worth of gold but managed to hide in Laos before returning to commit another crime.
He was reportedly adept at covering up his fingerprints and vehicle routes.