Here:

Question presented:

Whether respondents—Indians charged with felony assault in Indian country under the Major Crimes Act in violation of 18 U.S.C. 113(a)(6) and (8) and 1153(a)— were entitled both to a jury instruction on a lesser included offense not listed in the Major Crimes Act and complete acquittal if the jury found them guilty of that lesser offense.

Lower court materials here.