Prosecutors contend Terrill was trying to help a Republican friend who was planning to run for her Senate seat.
Leftwich did not seek re-election, and did not get the state job. After the district attorney announced an investigation was under way, then-Gov. Brad Henry vetoed a reform bill creating the job at the medical examiner's office.
Terrill is no longer in the Legislature. Last year, he lost his election bid to become a Cleveland County commissioner.
Both deny wrongdoing. The maximum punishment for a conviction in the felony case is two years in prison and a $5,000 fine.
Both likely to seek separate trials
The two now are scheduled to be tried together before the same jury. Terrill is asking for a separate trial. Leftwich is expected to make the same request.
The case has been delayed because prosecutors sought unsuccessfully to add a conspiracy count. A preliminary hearing judge ruled in 2011 that there was insufficient evidence for a conspiracy count. An appeals court last month upheld the ruling.