How I see it, as nobody witnessed the murders occurring, no witnesses could’ve known for sure they spotted the killer. Based on whatever they told LE, it was LE who determined it was a legitimate sighting.
A whole lot of weight has been placed on the accuracy of the sketches (too much IMO). Imagine if a witness had went public and eventually there is an arrest but the sketch the witness assisted in creating looked nothing like him other than he was caucasian with two eyes, a nose and mouth - imagine the public rage that would be directed toward this person for leading the public astray and impeding an arrest from occurring sooner. All those FB members searching, searching for look-alike images, what a waste.
If I were a possible witness involved in circumstances such as that, no way would I want my name out there especially prior to an arrest. I probably wouldn’t be able to sleep at night still wondering if the sketch resembles the person I saw, even in the slightest.