>If they took samples, that's no guarantee the samples were processed.
True. Failure to process could be for any number of reasons but chief among them would be the BPD's myopic viewpoint of parental involvement.

Consider how in the Elizabeth Smart case, clues that did not involve their prime suspect, Ricci, were at best downgraded and sometimes simply ingnored.

Sometimes things go really wrong for reasons that later seem almost comical:
A computer entry is made for Montana but mistakenly the clerk enters the abbreviation "MO" which is Missouri.
A multi-digit serial number on a firearm is entered with one transposition and the pistol is returned to the suspect who later kills several people in a bank robbery.
Some dim bulb hears Emmanuel and thinks its Immanual so the computer doesn't find the proper entry.

But a pervasive attitude that starts at the level of the Chief of Police and continues down to virtually all of the investigators is a force that is far more powerful than can be imagined.
So much time and effort was expended by the BPD on a wild goose chase and on defending their image that DA Keenan is only now starting an investigation into what is clearly a cold case. Most 'cold case' files go cold for a variety of reasons, but in the JBR case, the BPD's investigation did not "go cold". It never really got started. It was not an 'investigation', it was a "campaign".