No jurisdiction in the U.S. says that a prosecutor must use both of the above types of evidence to convict a defendant. A prosecutor can, in fact, secure a conviction by using only indirect evidence. For example, he/she can use this evidence to prove or disprove: the elements of the crime, the completion of certain acts, and the intent or mental state of the defendant. When using only circumstantial evidence, a criminal defense lawyer can try and show that there is a reasonable doubt as to guilt by demonstrating that: the evidence supports reasonable conclusions, and these conclusions are separate from a finding of guilt.