What is the burden of proving that a lineup is unreliable?

A defendant challenging the reliability of a lineup procedure bears the burden of demonstrating the procedure employed was (1) unduly suggestive and unnecessary; and (2) the identification was unreliable, taking into account the witness's opportunity to observe the criminal during the crime; the witness's degree of attention; the accuracy of the witness's prior description of the criminal; the level of certainty demonstrated at the time of the identification, and the time between the crime and the identification. (People v. Ochoa (1998) 19 Cal.4th 353, 412.) "'If, and only if, the answer to the first question is yes and the answer to the second is no, is the identification constitutionally unreliable.'" (Ibid.) However, if the procedure is not impermissibly suggestive, our inquiry ends because there has been no due process violation. (Ibid.)