While I see where you're going with this, let's take a moment to remember that the Joint Terrorism Task Force is made up of individual law enforcement officers,

While I see where you're going with this, let's take a moment to remember that the Joint Terrorism Task Force is made up of individual law enforcement officers, not agencies. That is to say that not all members of the Whatever County Sheriff's Department are inherently part of the Joint Terrorism Task Force. So it's certainly possible that three black SUVs worth of the local sheriff's deputies, all of whom were members of the Joint Terrorism Task Force, showed up to question her about her internet searching. Or this fiction writer is not portraying an accurate version of the events.