Okla. Stat. tit. 21, § 797
Robbery in the first degree is when, in the course of committing the theft, the defendant:
4. commits or threatens to commit a felony upon the person.
When accomplished in any other manner, it is robbery in the second degree.
R.L. 1910, § 2370; Amended by Laws 2001, SB 397, c. 437, § 4, eff. July 1, 2001 (superseded document available).