In the case of a false accusation, the less evidence the police gather the better the case for the state will be against you.

They don't need material or corroborating evidence for conviction. So the less they look into a particular case, the stronger the states case will be.

So for example, given two scenarios:

Scenario 1: Bill is accused of touching a women inappropriately, however Bill and Suzy have exchanged over 10,000 text messages and they were in a bar with cameras when the occasion occurred.

Scenario 2: Bill is accused of touching a women inappropriately. Bill has never met Suzy. Bill has never texted her, called her and the place where the accusation occurred did not have surveillance videos.

Police LOVE scenario 2. Scenario 2 provides the vacuum of information desired.

When you are innocent, you need to prove your innocence to a measure of evidence far beyond what is needed to convict you. Your testimony, will not matter. Your lifetime of character will not matter. The state will only consider what you say IF you have a level of evidence they do not expect of themselves. So they will throw you in jail for decades on merely a verbal accusation, whereas if you are going to prove your innocence you need direct and indisputable physical evidence.

If they know, your likely innocent they will be intentionally lazy to gather evidence. Because the more truthful facts they gather, the more it will conflict with their narrative.

Basically the less facts their are, the more they can fill the narrative with their deceptions and then throw it in front of a jury where they will evoke emotional responses to their false narrative.

An innocent person will beg for evidence to be presented, the state knows it doesn't need any to convict you and will intentionally avoid investigating, interviewing and preparing a strong case.

The less evidence they gather against an innocent individual, the stronger the states case is against you.

All they need is a place, time and narrative. That's it. That's all they want.

They know the bar of evidence to send a man to prison for life is on the floor and they are fully aware of this.