Okla. Stat. tit. 12, § 12-2405: Methods of proving character

A. Where evidence of a person's character or trait of character

is admissible, proof may be by testimony as to reputation or by

testimony in the form of opinion. Inquiry is allowable on cross-

examination into relevant specific instances of conduct.

B. In cases in which a person's character or a trait of

character is an essential element of a charge, claim or defense,

proof may be made of specific instances of his conduct.