In February, when the Fort Worth City Council considered the police department’s request to spend $184,000 on technology for tracking cell phone locations, approval was unanimous, without debate, and with only a few curious details revealed.

In a memo to the council, police officials promised to use the new system, called KingFish, “to establish probable cause” in criminal cases. Thing is, probable cause — that is, enough evidence to establish that there is probable cause to believe a crime has occurred — is what a law enforcement agency usually needs first, to convince a judge to approve invasive measures such as home searches, arrests, wiretaps or, in some contexts, use of tracking technology against an individual.

Police did not return Fort Worth Weekly’s calls seeking information for this story.