But according to a Kenyan intelligence official, the small shop concealed an ominous secret. It was rented by the Al-Shabaab terrorists, or their associates, who within a year would carry out an attack on the upscale shopping mall.

The information — revealed Friday to CNN by the source, who is close to the investigation into the attack — suggests the Somalian terror organization had been planning the operation at least that long.

How the team of terrorists got their weapons and explosives into the mall without notice is a central part of the investigation into the attack, which left at least 67 people dead and parts of the upscale mall in ruins.