Mr. Zheng Yang, led police to a pedestrian bridge crossing Khlong Phadung Krungkasem, near Hua Lampong railway station where he claimed he threw his walkie-talkie into the canal during his escape after the robbery failed.
He then went to the railway station to book a ticket to Chiang Mai from where he would travel to Chiang Rai and left the country for China on the R3A route or Chiang Rai â€“ Kunmin road.
After the reenactment, he said he intended to rob the gunshop because handgun could fetch very high price in China.
He said he arrived in Thailand late last month while other members came separately.
He will be brought to the Criminal Court Monday to have Courtâ€™s permission for detention for questioning.
Yesterday tourist police in Phuket also escorted a Chinese businessman, Su Su, 29, from Phuket to Bangkok for questioning as he is the person who was claimed by the gang leader to have provided mobile phone SIM cards for the gang.
He was found to activate a SIM card for Sun Junwei, 27, one of the four Chinese robbers who entered the gunshop on Friday.
Su is now being detained at the Immigration Bureau ahead of deportation.
Three others are Wu Xingjun, 40, Li Kunpeng, 26, and Ma Geng, 34. Wu died at hospital of shot wounds, while Sun and Ma were injured.
But acting metropolitan police commissioner Pol Lt Gen Sanit Mahathavorn said yesterday the police didnâ€™t believe in everything the suspects said.
He said police would piece together all evidence and also seek more information from the Chinese embassy.