I have read this question (which is closed) and already answered.
Quoting the answer:
There is no location transmitted within a normal SMS message (unless added by the author) so as the recipient of an SMS you won't normally be able to determine the location of the sender.
The location of a cell phone can be determined with varying precision by the Mobile Network Operator and any third parties with access to the MNO's system or data. The location precision depends on the capabilities of the device, the cell tower(s) it connects to and the quality of the signal.
So this makes the answer to the question HOW to locate the sender.
But lets say that the attacker goes to an unknown location with his turned off cell phone, inserts the prepaid SIM card in, turns the device on an sends an SMS message or a call with is (something illegal) i.e. death threat. He delivers the message, removes the SIM card and turn off the cell phone.
My question using the quoted answer: When can they trace him?
- Do they need to detect his registration to the mobile network tower as he turn his mobile phone on?
- Or is it enough that he logged in to the mobile network and left enough data to analyze it later do determine where he was.