Someone was asking me the other day about the difference between direct evidence and circumstantial evidence. The D.C. Criminal Jury Instructions provide a very helpful explanation:
There are two types of evidence from which you can determine what the facts are in this case – direct evidence and circumstantial evidence. When a witness, such as an eyewitness, asserts actual knowledge of a fact, that witness’ testimony is direct evidence. On the other hand, evidence of facts and circumstances from which reasonable inferences may be drawn is circumstantial evidence.
Let me give you an example. Assume a person looked out a window and saw that snow was falling. If he later testified in court about what he had seen, his testimony would be direct evidence that snow was falling at the time he saw it happen. Assume, however, that he looked out the window and saw no snow on the ground, and then went to sleep and saw snow on the ground after he woke up. His testimony about what he had seen would be circumstantial evidence that it had snowed while he was asleep.
The law says that both direct and circumstantial evidence are acceptable as a means of proving a fact. The law does not favor one form of evidence over another. It is for you to decide how much weight to give to any particular evidence, whether it is direct or circumstantial. You are permitted to give equal weight to both. Circumstantial evidence does not require a greater degree of certainty than direct evidence. In reaching a verdict on this case, you should consider all of the evidence presented, both direct and circumstantial. D.C. Criminal Jury Instruction 2.109