New Delhi, June 6 -- A runoff election Sunday will allow Peruvians to choose their ninth president in just 10 years, either the conservative daughter of a disgraced former president or a nationalist congressman.

Keiko Fujimori and Roberto Sanchez beat 33 other candidates in an April contest with promises to end rising crime, the top priority for Peruvians who have seen the country's homicide rates double and cases of extortion soar this decade. Still, each received less than 20% of support.

Sunday's results are expected to be tight, and the final outcome may not be known for days. Electoral authorities took more than a month to officially declare Fujimori - daughter of the late and convicted former president Alberto Fujimori - and Sanch...