Unlike Socrates, we know almost nothing about the person bearing the name Diogenes Laertius. We don't even know if the name Laertius comes from the town he was born in, or from an old Roman family name. We don't know when he was born, even to within a decade or two, and the same is true concerning the date of his death. Nor do we know where he was born (although the town of Laerte in Anatolia is one candidate), or where he lived and worked (and what he might have worked at, other than writing his Lives). The most we can say is that he lived sometime during the 3rd century AD, that he wrote in Greek, and that he appears to have been an especial admirer of Epicurus, whose "Life" is several times longer than that of any of the other 44 "Eminent Philosophers" he writes about. Modern scholars consistently warn against too much reliance on old DL, yet his Lives and Opinions of Eminent Philosophers continues to be one of the most important, and most often cited, documents in the history of ancient philosophy.
The followers of Epicurus, with whom DL seems to have been aligned, were among the least "Socratic" of all the ancient schools. For example, the Epicureans explicitly rejected the use of "dialectic", the mainstay Socrates' philosophical "style", which many consider to be synonymous with the very activity of "philosophizing" itself. But the philosophers of "the Garden" found dialectic to be "confusing" (parelkousa) and of no use in arriving at truth. Nevertheless the universal admiration for Socrates shared by all Hellenes in the ancient world who were in any way philosophically inclined, shows clearly in DL's writing. The following is all of what he says concerning the Trial of Socrates:
XVIII. [T]he priestess at Delphi was witness in his favour, when she gave Chaerephon this answer, which is so universally known:
Socrates of all mortals is the wisest.In consequence of which answer, he incurred great envy; and he brought envy also on himself, by convicting men who gave themselves airs of folly and ignorance, as undoubtedly he did to Anytus; and as is shown in Plato's Meno. For he, not being able to bear Socrates' jesting, first of all set Aristophanes to attack him, and then persuaded Melitus to institute a prosecution against him, on the ground of impiety and of corrupting the youth of the city. Accordingly Melitus did institute the prosecution; and Polyeuctus pronounced the sentence, as Favorinus records in his Universal History. And Polycrates, the sophist, wrote the speech which was delivered, as Hermippus says, not Anytus, as others say. And Lycon, the demagogue, prepared everything necessary to support the impeachment; but Antisthenes in his Successions of the Philosophers, and Plato in his Apology, say that these men brought the accusation: Anytus, and Lycon, and Melitus; Anytus, acting against him on behalf of the magistrates, and because of his political principles; Lycon, on behalf of the orators; and Melitus on behalf of the poets, all of whom Socrates used to pull to pieces. But Favorinus, in the first book of his Commentaries, says, that the speech of Polycrates against Socrates is not the genuine one; for in it there is mention made of the walls having been restored by Conon, which took place six years after the death of Socrates; and certainly this is true.
XIX. But the sworn informations, on which the trial proceeded, were drawn up in this fashion; for they are preserved to this day, says Favorinus, in the temple of Cybele: "Melitus, the son of Melitus, of Pittea, impeaches Socrates, the son of Sophroniscus, of Alopece: Socrates is guilty, inasmuch as he does not believe in the Gods whom the city worships, but introduces other strange deities; he is also guilty, inasmuch as he corrupts the young men, and the punishment he has incurred is death."
XX. But the philosopher, after Lysias had prepared a defence for him, read it through, and said-"It is a very fine speech, Lysias, but is not suitable for me; for it was manifestly the speech of a lawyer, rather than of a philosopher." And when Lysias replied, "How is it possible, that if it is a good speech, it should not be suitable to you?" he said, "Just as fine clothes and handsome shoes would not be suitable to me." And when the trial was proceeding, Justus, of Tiberias, in his Garland, says that Plato ascended the tribune and said, "I, men of Athens, being the youngest of all those who have mounted the tribune ... and that he was interrupted by the judges, who cried out katabantôn, that is to say, 'Come down.'
XXI. So when he had been condemned by two hundred and eighty-one votes, being six more than were given in his favour, and when the judges were making an estimate of what punishment or fine should be inflicted on him, he said that he ought to be fined five and twenty drachmas; but Eubulides says that he admitted that he deserved a fine of one hundred. And when the judges raised an outcry at this proposition, he said, "My real opinion is, that as a return for what has been done by me, I deserve a maintenance in the Prytaneum for the rest of my life." So they condemned him to death, by eighty votes more than they had originally found him guilty. And he was put into prison, and a few days afterwards he drank the hemlock, having held many admirable conversations in the meantime, which Plato has recorded in the Phaedo.
XXII. He also, according to some accounts, composed a paean, which begins
Hail Apollo, King of Delos,But Dionysidorus says that this paean is not his. He also composed a fable, in the style of Aesop, not very artistically, and it begins-
Hail Diana, Leto's child.
Aesop one day did this sage counsel giveXXIII. So he died; but the Athenians immediately repented3 of their action, so that they closed all the palaestrae and gymnasia; and they banished his accusers, and condemned Melitus to death; but they honoured Socrates with a brazen statue, which they erected in the place where the sacred vessels are kept; and it was the work of Lysippus. But Anytus had already left Athens; and the people of Heraclea banished him from that city the day of his arrival. But Socrates was not the only person who met with this treatment at the hands of the Athenians, but many other men received the same: for, as Heraclides says, they fined Homer fifty drachmas as a madman, and they said that Iystaeus* was out of his wits. But they honoured Astydamas, before Aeschylus, with a brazen statue. And Euripides reproaches them for their conduct in his Palamedes, saying:
To the Corinthian magistrates: not to trust
The cause of virtue to the people's judgment.
Ye have slain, ye have slain,
O Greeks, the all-wise nightingale,
The favourite of the Muses, guiltless all.
[taken from here]
The Varieties of Sceptical Thought:
 Sceptical Scepticism
 Socrates on Death
 Socrates' Advice to the Jury
 Richard Popkin
 Overview of the Trial of Socrates
 "Socrates of all mortals is the wisest"