his actions should be denounced by the Muslim community.
It is not the job of any minority community to denounce members of that community when they do heinous things. If a black man stabs a white man because he hates white people, no one would be calling on the black community specifically to denounce him (except maybe Republicans).
He committed murder. There’s no need to make some public denouncement. He’s on video attempting to commit the murder. He’s been arrested for attempted murder. He’s clearly a guy who planned to commit a murder. He can say it was for Palestine, but that doesn’t make Palestinians responsible and it certainly wouldn’t make, for example, a Muslim from Indonesia responsible.