Police in St Petersburg have arrested an elderly pensioner suspected of killing at least a dozen people over the last two decades. RT's Ilya Petrenko followed the traces left by the serial killer. br br RT LIVE br Subscribe to RT! br Like us on Facebook Follow us on Twitter Follow us on Instagram Follow us on Google+ Listen to us on Soundcloud: br RT (Russia Today) is a global news network broadcasting from Moscow and Washington studios. RT is the first news channel to break the 1 billion YouTube views benchmark.