Normally a terrorist group claims responsibility and makes demands. Vandals generally don’t. Call it what you like, but it’s unknown who is responsible.
> Normally a terrorist group claims responsibility and makes demands
Making-demand (AKA hostage-taking) terrorism was mostly a phenomenon of the 1970s and 1980s, mostly in the form of flight hijackings, and was usually carried out by state-affiliated terrorists, who had an objective to negotiate for prisoner releases.
The violence/fear-as-the-objective type of terrorism has been the predominant since the Oklahoma City bombing onwards to the Salafist terrorism of the last few decades and through to the current spate of white-supremacist motivated terror attacks (i.e. Buffalo). There was quite a bit of this sort of terrorism going on in the US prior to the Civil Rights movement, too, but we didn't have the word "terrorism" to apply to things like lynchings.
Claiming responsibility is not useful for domestic terrorists as they can then be easily captured compared to those who reside in hostile states. Also, claiming responsibility also has the effect of reducing panic and confusion, which is the opposite of what these groups want to accomplish. Timothy McVeigh didn't claim responsibility for the Oklahoma City bombings. He was tracked down (despite his use of aliases to rent the truck) by FBI agents:
