A fact can be proved by either direct evidence or circumstantial evidence, or by both.
If an eyewitness testifies about what the witness saw, that is an example of direct evidence.
If the ground is bare when you go to sleep but is covered with a blanket of snow when you awake, this is circumstantial evidence that it snowed while you were asleep.
A person can be convicted on circumstantial evidence alone if the circumstantial evidence is consistent. If one piece of circumstantial evidence contradicts another piece of circumstantial evidence, the circumstantial evidence is not consistent. You can convict a person on circumstantial vidence alone if the circumstances proved exclude every reasonable theory except that the accused is guilty.
State v. Steele, 211 N.W.2d 855 (N.D. 1973)
State v. Tucker, 58 N.D. 92, 224 N.W. 878 (1929)
BAJI 2.00 and 2.01