The political elites of Athens clearly wanted him dead. There wasn't a compelling reason to offer him exile.

If you are characterizing the trial as the result of an angry mob I think you are misunderstanding the context. Throughout the Meno and the Crito, Plato takes pains to draw that it was Anytus that was one of the leading figures in bringing the trial. This was a result of the upper class of Athens being humiliated by Socrates students who would often disgrace their high noble elders for the sheer fun of it. None of this was really due to the urging of Socrates, yet the effect on the established upper class made Socrates a danger in his mind.

I would struggle to come up with a literary reference since my comments are based on my readings of Plato and college lectures that I have seen on youtube.

In terms of a more direct citation we can look to Socrates on Trial by Thomas Brickhouse

The indictment against Socrates was made by Meletus. The procedure appears to have followed the requirements of a Athenian legal due process, according to which the indictment was brought to the King-Archon, who convened a preliminary hearing to decide if the case was sufficiently serious to merit a trial.

You can see from that passage that the procedure is actually very similar to a grand jury indictment. This was not the actions of a rabble mob at all.

The details in that source are actually pretty interesting. After that initial hearing the matter was sent to a specific court to try for piety. By custom of the charges it was actually Meletus who suggested at the conclusion of his indictment speech that set the proposed punishment of death.

Also interestingly if that "grand jury" proceeding failed to show just cause for trial they would have to pay penalties. There is also some commentary that the evidence against Socrates was scant, yet the King-Archon still forwarded the case to trial.