reasons.

First, their case is entirely dependent upon the prostitute showing up for trial. The odds of that happening were always slim. It's likely the State had to report to the judge that they no longer have any contact with her and will not be able to proceed to trial.

Second, in the unlikely event she is cooperating with the State, proof beyond a reasonable doubt was going to be hard to establish. While they have Wests own admission to trying to hire the prostitute (including his statement he wasn't going to steal from the hooker he was going to steal the money to pay her from his brother), and apparently some physical evidence (her injuries and description of the knife found in the kitchen), this stills involves a lot of credibility issues. I'll bet that the State offered a plea to a misdemeanor and the defense rejected it (even assuming the "victim" was cooperating).