We have compared the decay rates of K-L and K-S to pi(+)pi(-) and pi(0)pi(0
) final states using a subset of the data from the KTeV experiment (E832) a
t Fermilab. We find that the direct-CP-violation parameter Re(epsilon'/epsi
lon) is equal to [28.0 +/- 3.0(stat) +/- 2.8(syst)] x 10(-4). This result d
efinitively establishes the existence of CP violation in a decay process.