Kenya's Deputy President William Ruto picked a former aide turned fierce critic of President Uhuru Kenyatta to be his running mate in the country's high-stakes election in August. Rigathi Gachagua, who served as Kenyatta's personal assistant between 2001 and 2006, was picked after a months-long, secretive process marked by intense lobbying. FILE IMAGES of Kenya presidential opposition candidate William Ruto appointing former Kenyatta aide, Rigathi Gachagua, as his running mate