Immediately enlisting in the United States Navy, he spent the final year of World War II, on reserve duty in the South Pacific.

Following graduation from law school, he became Assistant City Attorney in Tulsa, before joining a private practice in Claremore, Oklahoma.

[3] Lavender was still in private practice when Governor Henry Bellmon appointed him to fill a vacancy on the Oklahoma Supreme Court on June 24, 1965,[6] representing the 1st District.

It is my opinion that a strong and independent judiciary composed of men of unimpeachable integrity is an absolute essential to the continuation of our society.”[9] Governor Henry subsequently appointed John F. Reif to succeed Justice Lavender.

Lavender's wife worked as a child development specialist and as a consultant for blind and visually-impaired students in nearby school districts.