Circumstantial evidence
In practice, circumstantial evidence can have an advantage over direct evidence in that it can come from multiple sources that check and reinforce each other. Eyewitness testimony can be inaccurate at times, and many persons have been convicted on the basis of perjured or otherwise mistaken testimony. Thus, strong circumstantial evidence can provide a more reliable basis for a verdict. Circumstantial evidence normally requires a witness, such as the police officer who found the evidence, or an expert who examined it, to lay the foundation for its admission. This witness, sometimes known as the sponsor or the authenticating witness, is giving direct (eyewitness) testimony, and could present credibility problems in the same way that any eyewitness does.