The trial
The trial scene seemed rather lacking in tension: given that Ferlinghetti had opted to waive his right to a jury trial, I wonder if he had been advised that he didn't have much to worry about. Certainly it would have been almost impossible to prove that the poem was entirely without literary merit.
It's interesting to compare it with our own celebrated obscenity trial: Penguin Books were prosecuted in 1960 for publishing Lady Chatterley's Lover. A big difference is that the author was not a little-known, previously unpublished poet but an acknowledged classic author championed by the influential critic FR Leavis. One thing the two trials did have in common was a certain snobbish attitude towards the great reading public: both prosecuting counsels warned of the dangers of the works falling into the hands of "ordinary people" who didn't have the fancy education of the defence witnesses. Though at least the prosecutor in the Howl trial didn't go as far as his British counterpart, who asked the jury if Chatterley was a book they would want their "wives and servants" to read.