Elsa and Luke were no longer partners but still in the same team. They could work on more cases, and their abilities wouldn't go to waste.
At Luke's heads-up, Elsa found an important lead and solved the William Johnson case.
The DNA test on the blood left behind by the wounded female shooter confirmed that she was the sister of the college student suspected of dying from a drug overdose.
In the end, it was discovered that the shooter was the elder sister who went missing as a child, and the college student was the younger sister.
There was no telling how they met, but the younger sister, who studied at USC, moved into her elder sister's apartment.
William claimed ownership of the building not long ago, and wanted to drive out Rebecca, the elder sister, who had signed a long-term lease.
But Rebecca wasn't living in the apartment, though she was paying the rent.
