Only when we have an understanding of that, we can assign evidential value to that trace evidence.

只有掌握点，才能给个痕迹证据添加证据价值。

There has to be a high level of evidential justification to deploy this type of technology and I just don't think it's there.

要部署技术，必须要有高水平的证据认证，但我不认为会有。

And since much of the new tech invades personal privacy it should only be introduced with evidential justification – explanation of why it is the right thing to do, based on evidence.

，由于许多新技术侵犯个人隐私，些技术的采用需要证据认证——基于证据解释为什么做某件事是对的。