What is Circumstantial Evidence?

Before analysing the factual aspects it may be stated that for a crime to be proved it is not necessary that the crime must be seen to have been committed and must, in all circumstances be proved by direct ocular evidence by examining before the court those persons who had seen its commission. The offence can be proved by circumstantial evidence also. The principal fact or factum probandum may be proved indirectly by means of certain inferences drawn from factum probans, that is, the evidentiary facts. To put it differently, circumstantial evidence is not direct to the point in issue but consists of evidence of various other facts which are so closely associated with the fact in issue that taken together they form a chain of circumstances from which the existence of the principal fact can be legally inferred or presumed.

Supreme Court
Liyakat vs State of Uttaranchal, Appeal (Crl.) 378 of 2008

“8. There is no eyewitness to the occurrence and the entire case is based upon circumstantial evidence. The normal principle is that in a case based on circumstantial evidence the circumstances from which an inference of guilt is sought to be drawn must be cogently and firmly established; that these circumstances should be of a definite tendency unerringly pointing towards the guilt of the accused; that the circumstances taken cumulatively should form a chain so complete that there is no escape from the conclusion that within all human probability the crime was committed by the accused and they should be incapable of explanation of any hypothesis other than that of the guilt of the accused and inconsistent with their innocence vide Sharad Birdhichand
Sarda v. State of Maharashtra [Sharad Birdhichand Sarda v. State of Maharashtra, (1984) 4 SCC 116 : 1984 SCC (Cri) 487]. The same view was reiterated in Bablu v. State of Rajasthan [Bablu v. State of Rajasthan, (2006) 13 SCC 116 : (2007) 2 SCC (Cri) 590].”

Supreme Court
Vijay Shankar v. State of Haryana (2015) 12 SCC 644

Essential Conditions to Prove Circumstantial Evidence – Standard of Proof