Anonymous death threat text

A friend of mine and her sister were receiving harassing text, that included death threats. They also knew where they were at all times and what was being said. The local police were following them as they thought they were being followed and stopping anyone who thought they may be following them. It was determined …duh that there was spyware on her phone but apparently cant be proven who did it.
My friend figured out who it was once they figured out the spyware thing, as there were no people who had access to her phone but them. So far nothing has happened except her phone was wiped and of course they couldn’t hear conversations anymore or know where they are and act as if they were around watching them.
They still continued the anonymous texting with threats and finally just quit. Why cant the police (I believe the FBI was even involved) get proof of who did this. To me it seems simple, as they would have probable cause to get the persons phone record who had access to her phone. How did they do this?

If the phone was “wiped” (1) how is the FBI supposed get proof the messages were sent and (2) that there was actually “spyware” used. Phone companies do not retain text data. Other than a possible phone record that a call or text was made to your sister’s number how is the FBI supposed to make all this happen for your sister now that the evidence has been wiped?

Gawd amighty, do you have a pronoun problem.

What’s an anonymous text?

Mr Pham, Thanks for pointing that out, really wasnt aware but since they told me that before :wink:

Astro, I should have reread and edited my post as it is confusing, Wiped phone- I dont know except the police told my friend to take the phone to t mobile and have factory reset done. The police allegedly did this to determine if her sisters phone also had spyware on it. The sisters live in homes separate from each other, about two miles apart. That did determine that it was only on my friends phone and not her sisters as the the text to her sisters phone no longer made references to conversations or locations. The police saw the text and had both of them forward each one as they received them to the detective. This is the information I was given and basically nothing has been done. My question in this is why haven’t they been able to trace the spyware or the text to an address or name? I dont understand how someone did all this and has been able to get away with it? Or maybe the police are just being quiet about it and still working on it. My friend is positive who did it because of phone access unless they remotely put the spyware on her phone. Is that possible?

Ambivalid- My friend told me that the person who did this generated an untraceable number. These were the exact words the police told her