Okla. Stat. tit. 63, § 63-2-431: Proof of participation in illegal drug market - Standard

of proof - Prima facie evidence of participation.

A. Proof of participation in the illegal drug market in an

action brought under the Drug Dealer Liability Act shall be shown by

clear and convincing evidence. Except as otherwise provided in this

act, other elements of the cause of action shall be shown by a

preponderance of the evidence.

B. A person against whom recovery is sought who has a criminal

conviction pursuant to state drug laws or the Comprehensive Drug

Abuse Prevention and Control Act of 1970 (Public Law 91-513, 84

Stat. 1236, codified at 21 U.S.C., Section 801 et seq.) is estopped

from denying participation in the illegal drug market. Such a

conviction is also prima facie evidence of the participation of the

person in the illegal drug market during the two (2) years preceding

the date of an act giving rise to a conviction.

C. The absence of criminal drug conviction of a person against

whom recovery is sought does not bar an action against that person.