The moment that they gave up such information, they would lose their value and even if they tried to withhold it for greater benefits, the information that they could provide would not be seen as being worth using such resources.
The moment that they gave up such information, they would be back on the streets again and if they were to be known as a snitch who talked to the cops and helped them in their investigation, their lives would become very difficult and their chances of survival would be lowered.
Such a small detail ended up causing a major halt in the investigation which resulted in there being an additional attempt from the police as they reached out to various media so that the public could come in and provide whatever help they could.
Unfortunately for them, the previous living address belonging to Cal could still not be discovered so they could not track him down.
