Circumstantial evidence is certainly sufficient to convict in most (if not all) US jurisdictions.

Since you mentioned secondhand information, I think you might be thinking of hearsay.

I wasn’t aware CCTV was ever called circumstantial. At which point does the principal end? Are forensics circumstantial because a police officer wasn’t there when the material was deposited?

Maybe this is me being naive?

Law and Order lied to us. Courts run on circumstantial evidence. A lot of cases turn on it.

For criminal law, prosecutors have to prove beyond reasonable doubt. If they have a gun, search history for "how to kill someone and get away with it", blood in their car, and someone that's been missing for an extended period of time. They can and have gotten convictions based on that. Hans Reiser was convicted under pretty much those circumstances.

Law and order lied to you. Circumstantial evidence can be enough for a conviction, provided that all the evidence adds up to enough to prove guilt beyond a reasonable doubt. And it can certainly provide a reasonable suspicion for a traffic stop.

Law and Order absolutely lied to you, in many ways. Video evidence is absolutely evidence. Also, the threshold for a traffic stop is very low. “I thought I saw something on a camera” absolutely meets the limit for a traffic stop.

Law and Order lied in many ways, but calling out evidence for being circumstantial isn’t one of them. “Circumstantial” doesn’t mean it doesn’t count, but it does discount its evidentiary strength.

Not only are you wrong, you are mixing up court evidence and police investigation.

Your fingerprint at a crime scene or DNA on a victim is circumstantial evidence. It is weaker evidence in court than hard evidence, but still valid.

This circumstantial evidence is more than sufficient to search your house or car and find a body (hard evidence).