Correction:They have the lab in-house, so they don't have to send the samples off to another lab; and they prioritise the cases by importance, so samples from the 'big' cases go first. DNA tests themselves don't take weeks, sending them off to a lab, and waiting for the lab to get around to testing them, does. Them having the lab in-house relies on suspension of disbelief, but isn't inherently a mistake.
Correction: They have the lab in-house, so they don't have to send the samples off to another lab; and they prioritise the cases by importance, so samples from the 'big' cases go first. DNA tests themselves don't take weeks, sending them off to a lab, and waiting for the lab to get around to testing them, does. Them having the lab in-house relies on suspension of disbelief, but isn't inherently a mistake.
J I Cohen