I didn't say it was "more likely", I said they could have done it without police assistance.
Being realistic, you know the relatives didn't fabricate the silencer alone. Not knowing 11 vital variables.
It was much too risky & the punishment if unsuccessful much too high.
You are just saying they could have to keep you're apparent 'on the fence' stance alive.
If the relatives couldn't fabricate the silencer alone, and the police didn't need the relatives to pretend they found it, how was the silencer fabricated ?