A day after security was beefed up at Kempegowda International Airport (KIA) following a bomb scare, investigators have zeroed in on the suspect, a techie with a private firm in the city, but are yet to establish the motive. The probe was handed over to the Central Crime Branch (CCB) late on Saturday evening. A series of WhatsApp messages to an airport official, claiming bombs had been planted inside three international flights, including one heading to Saudi Arabia, sent cops into a tizzy. Initially, the messages were tracked to an apartment in HSR Layout, southeast Bengaluru. But the resident in whose name the SIM was registered denied any role in the mischief. This was also corroborated by the SIM card dealer.