Internet searches

I watched a new 48 Hours mystery tonight and it got me to thinking. The husband in the show was using his cell phone to research his death plan and the police went thru his search history. This show brought back a memory I had forgotten about. Ex upgraded his phone from a Samsung to an iPhone shorty before I caught him with his affair partner. I looked through his iPhone and didn’t find anything suspicious. But Ex hung onto the Samsung and after I found out about the affair I discovered Ex was using the old disconnected Samsung for wifi internet searches.

But it makes me wonder. What if that husband had used an old disconnected phone for his evil searches instead of his current connected phone, would the police have found the evil searches?