Netenyahu might not be able to be detained as a head of state, but his consular staff can probably be arrested and detained for questioning. The Us did sign the geneva conventions and are legally bound to act on those. Even just cuffing them and marching them to a car would be great to see. And either way, Mamdani and his state police should be shadowing the war criminals everywhere he goes so that if any new yokrer is threatened or abused, he can step in and literally kick some ass.
Israeli diplomats have a history of roughing up protestors whose messages they dont like. Any of that should be met with immediate overwhelming force by the state of New York to protect the citizens of new york in their right to peaceful protest in the US. No halfassed apologies later, we need interverntion as it happens. If some diplomats get roughed up, well-- we can send an apology for that later. Israel just detained and pointed guns at Ro Khanna the other day. they deserve the same treatment. Guns aimed at their heads.

https://www.ejiltalk.org/the-universal-obligation-to-arrest-netanyahu-and-gallant-ending-state-officials-immunity-saga-with-respect-to-grave-breaches-of-ihl/