South African scientists have launched an anti-poaching campaign in which rhinos' horns will be injected with a radioactive material. The group, from the University of the Witwatersrand, said the process is harmless to rhinos but will allow customs officers to detect smuggled horns as they're transported across the world.

A new initiative in South Africa is safely placing radioactive isotopes into rhino horns and using existing nuclear security infrastructure to detect and deter illegal trade. Sean Hogan has more.