[pvarangot]

Legally getting that information from cellphone towers or tech companies and then acting on it would take at least one week, even if they had killed multiple people. A three letter agency could probably get it clandestinely and act para-legally for example putting people on surveillance or getting a flash arrest warrant for an unrelated but quickly to parallel-construct crime, but I don't see that happening in this case.

If there's going to be arrests based on cellphone tower or mobile app data I would expect them to happen by the end of next week.