And a term that I sometimes need to refresh myself on, grand jury

https://en.wikipedia.org/wiki/Grand_jury

There are details of a grand jury that I still don't fully understand. As best I comprehend it, it's a group of one's peers (regular citizens, not legal professionals) who review the evidence against a person, to determine from a layman's perspective whether the evidence is sufficiant to warrant an indictment and trial for a defendant.

If Law and Order episodes portray it accurately, grand juries can also be assembled to determine whether warrants can be issued. The last episode of Law and Order, titled "Rubber Room", had a person online boasting they were going to use guns and bombs to do a mass killing at a school (it turned out to be a suspended teacher). In the episode, a grand jury was summoned to get a warrant to go through students' computers and lockers to find the suspect. In the episode, the grand jury resisted that level of intrusion based on what they as laymen perceived as insufficient evidence.

I'm not clear on when a judge would authorize a warrant, vs. when a grand jury would authorize a warrant.