Defense attorney Dinora Dilone said Simon was acquitted Tuesday in the New Year's Eve shooting death of 25-year-old Michel Castillo Almonte.
Dilone says experts testified that the fatal bullet did not come from Simon's gun and that no witnesses saw the pitcher fire his weapon.
The victim's family had previously dropped a lawsuit against Simon, but the public prosecutor still pursued the case. It was not clear whether the prosecutor planned to appeal.
Simon faced up to two years in prison if convicted.