Investigators said they were "certain" that a man shown leaving a backpack at the scene of the explosion was responsible for the blast. The security camera footage, which has been broadcast internationally, shows the man in shorts and a yellow T-shirt taking off a dark-coloured backpack while sitting on a bench and then standing up, putting the backpack underneath the bench and walking away while looking at his phone.[18] The suspect likely had arrived by tuk-tuk from an alley near Hua Lamphong.[19]
Some newspapers alleged that the man captured on security footage at the Erawan Shrine bomb attack was named by authorities as Mohamad Museyin, and that investigators are focusing their efforts on budget Bangkok hotels in the Sathorn Road area where they believe the suspect stayed.[20] However, this information was quickly dismissed by Thai authorities.[21]
Thailand's chief of police said the attack was carried out by a network and issued a sketch of the suspect. Police are also saying that two other people seen in the same footage were being treated as suspects.[18]
A taxi driver later confirmed that he picked up the suspect, and described him as "not in a hurry. He seemed to be calm, like a regular customer, and not Thai. He also spoke in an unclear language on the way."[22]