The killer's face isn't visible in the February 14 footage, so Clearview couldn't identify them.
Undeterred, the cops used Clearview's facial recognition to identify a person in separate video surveillance captured days later on February 20, 2024. The US city's police themselves figured that person, on the basis of his clothing and the way he walked, may be the shooter in the February 14 footage, and obtained a search warrant against the computer-identified man.
So their whole case is that some dude walking down the street days later looked kinda like the guy. They have no other evidence to link him to the crime, other than a gun "officers believe is the murder weapon". The cops deserve to get laughed out of court and publicly humiliated for this.