A book of 524 pages published in 1911 was entitled Commentaries on the Law in Shakespeare: with Explanations of the Legal Terms used in the Plays, Poems and Sonnets; and discussions of the Criminal Types Presented, with its author, Edward J. White, declaring:
“In Shakespeare’s multiple personalities, there is none in which he appears more naturally and to better advantage than in the role of the lawyer. If true that all dramatic writing is but a form of autobiography, then the immortal Shakespeare must, at some time in his life, have studied law.”
There’s not a shred of evidence that William Shakspere of Stratford upon Avon ever went beyond grammar school (if he attended at all), much less to law school.

Edward de Vere Earl of Oxford served as highest-ranking nobleman on the tribunal at the February 19, 1601 treason trial of Essex and Southampton — as indicated by a contemporary notice of the event
On the other hand, Edward de Vere the 17th Earl of Oxford was seventeen in 1567 when he entered Gray’s Inn to study law. Oxford was steeped in legal matters involving his earldom and the royal court; he sat on the juries at the treason trials of the Duke of Norfolk (1572) and Mary Queen of Scots (1586) as well as the treason trial of the earls of Essex and Southampton (1601).
A more recent book, Shakespeare’s Legal Language (2000) contains more than 497 pages of detailed discussion of Shakespeare’s legal terms and concepts. The authors, B.J. Sokol and Mary Sokol, point out that twenty-five of thirty-seven Shakespeare plays refer to a trial and that thirty-five of his plays contain the words “judge” and “justice.”
“Nothing adorns a king more than justice,” Oxford wrote to Secretary Robert Cecil in May 1603, referring to the newly proclaimed King James. “Nor in anything doth a king more resemble God than in justice.”

James Plaisted Wilde, the Lord Penzance (1816-1899), the noted British judge who believed that Francis Bacon was author of the Shakespeare works; but that was before J. Thomas Looney identified the Earl of Oxford in 1920
Scholars upholding the Stratfordian view of authorship keep trying to tell us that Shakespeare didn’t really have any exceptional knowledge of the law, but at the same time they keep attempting to explain how he could have become so “law-obsessed,” as Sokol & Sokol put it.
Back in 1869, for example, Lord Penzance spoke of Shakespeare’s “perfect familiarity with not only the principles, axioms, and maxims, but the technicalities of English law, a knowledge so perfect and intimate that he was never incorrect and never at fault … At every turn and point at which the author required a metaphor, simile, or illustration, his mind ever turned first to the law. He seems almost to have thought in legal phrases…”
“Any intelligent writer can acquire knowledge of a subject and serve it up as required,” Charlton Ogburn Jr. wrote in The Mysterious William Shakespeare (1984), adding that it is “something else to have been so immersed in a subject and to have assimilated it so thoroughly that it has become part of one’s nature, shaping one’s view of the world, coming forward spontaneously to prompt or complete a thought, supply and image or analogy.”

Oxford served on the jury at the trial of Mary Queen of Scots at Fotheringay Castle in October 1586 (drawing by Edouard Berveiller)
The literature on Shakespeare’s legal knowledge is extensive. For suggested reading I recommend Mark Alexander’s study “Shakespeare’s Knowledge of the Law: A Journey through the History of the Argument,” and the Shakespeare Fellowship page on “Shakespeare and the Law.”
“Shakespeare couldn’t have written Shakespeare’s works,” Mark Twain wrote, referring to Shakspere of Stratford, “for the reason that the man who wrote them was limitlessly familiar with the laws, and the law-courts, and law-proceedings, and lawyer-talk, and lawyer-ways—and if Shakespeare was possessed of the infinitely-divided star-dust that constituted this vast wealth, how did he get it, and where, and when? . . . [A] man can’t handle glibly and easily and comfortably and successfully the argot of a trade at which he has not personally served. He will make mistakes; he will not, and cannot, get the trade-phrasings precisely and exactly right; and the moment he departs, by even a shade, from a common trade-form, the reader who has served that trade will know the writer hasn’t.”
Here’s a patchwork of snippets from Oxford’s letters showing him to be involved in matters of law, with my emphases:
“But now the ground whereon I lay my suit being so just and reasonable … to conceive of the just desire I make of this suit … so byfold that justice could not dispense any farther … The matter after it had received many crosses, many inventions of delay, yet at length hath been heard before all the Judges – judges I say both unlawful, and lawful … For counsel, I have such lawyers, and the best that I can get as are to be had in London, who have advised me for my best course … [to Queen Elizabeth]: And because your Majesty upon a bare information could not be so well satisfied of every particular as by lawful testimony & examination of credible witnesses upon oath … So that now, having lawfully proved unto your Majesty … “
Oxford attended at the House of Lords on forty-four days during the nine sessions held from 1571 to 1601. In the sessions from 1585 onward he was appointed one of the “receivers and triers of petitions from Gascony and other lands beyond the seas and from the islands.” In November of 1586 he was part of a committee appointed to address Elizabeth on the sentencing of Mary Queen of Scots.
Let us close out this reason why Oxford was “Shakespeare” with Sonnet 46:
Mine eye and heart are at a mortal war
How to divide the conquest of thy sight;
Mine eye, my heart thy picture’s sight would bar
My heart, mine eye the freedom of that right;
My heart doth plead that thou in him dost lie
(A closet never pierced with crystal eyes),
But the defendant doth that plea deny,
And says in him thy fair appearance lies.
To ‘cide this title is impanelled
A quest of thoughts, all tenants to the heart,
And by their verdict is determined
The clear eyes’ moiety, and thy dear heart’s part:
As thus, mine eyes’ due is thy outward part,
And my heart’sright, their inward love of heart.