Rule 702.        Testimony by Experts

If scientific, technical, or other specialized knowledge will

assist the trier of fact to understand the evidence or to

determine a fact in issue, a witness qualified as an expert by

knowledge, skill, experience, training, or education, may

testify thereto in the form of an opinion or otherwise, if (1)

the testimony is based upon sufficient facts or data, (2) the

testimony is the product of reliable principles and methods,

and (3) the witness has applied the principles and methods

reliably to the facts of the case.