What Happens if a Defendant Passes a Polygraph?

A trial court cannot admit the results of a polygraph test into evidence
simply at an accused’s request.
State v. Jamison, 49 Ohio St.3d 182, 190, 552 N.E.2d 180 (1990). A trial court can only
admit polygraph test evidence if the prosecution and defense together
stipulate beforehand that the defendant will take the polygraph and that
the results of which test will be admitted to the court.
Id.;
State v. Souel, 53 Ohio St.2d 123.

In the event of a stipulation, the results of the polygraph test stil can
only be admitted to the trial court if the court determines it is acceptable
for corroboration or impeachment purposes. There is at least one reported
decision in Ohio that finds polygraph results to be reliable on their own.
State v. Sharma, 143 Ohio Misc.2d 27, 875 N.E.2d 1002, 2007-Ohio-5404(C.P.) (polygraph test
results sufficiently reliable to permit their admission at trial).

If the defendant wants polygraph results admissible in his trial then (a)
he needs to get the results stipulated by the prosecution (b) he better
pass the polygraph and (c) convince the judge to let a jury hear the results.
It is still very rare for a jury in Ohio to ever hear about polygraph
results of an accused.