For conviction I agree, for suspicion not so much. Suspicion isn't guilt. The authorities should suspect people based on probable cause, courts should presume innocence and require the state builds a flawless argument beyond reasonable doubt.
Except it doesn't work like that in practice. It would be nice if it did. Often a person can be found guilty simply by jury in a trial based on what they think a person might have done. That's reality, and it is the case in western would countries not some obscure dictatorship.
This is a common pattern I'm seeing in recent discussions. There is a practical problem, so instead of fixing the problem, let's not use the system entirely. Perhaps for victimless crimes I would agree with you, but it is not for you or I but for the victims or whoever is survived by them to relinquish their demand for justice.
For serious crimes, suspicion must be corroborated by evidence. hear-say, accusations or eye-witness testimony alone can't be used to even begin a trial.