The War Department's detective chief helped run the hunt for Lincoln's killer and later testified that pages had been cut from John Wilkes Booth's diary after it was handed to the Secretary of War.
Lafayette C. Baker headed the National Detective Police, the War Department's detective force during the Civil War, a separate body from today's U.S. Secret Service [1].
Before April 1865 Edwin Stanton, the Secretary of War (the cabinet member in charge of the Army), had sent him to New York, in effect banishing him, after finding Baker had tapped Stanton's own telegraph lines. On 15 April, the day Abraham Lincoln died, Stanton wired him to come and find the murderers. Baker reached Washington on 16 April (one account says morning, another afternoon). On 24 April he placed a cavalry detachment under the control of the detective Everton Conger for the manhunt for John Wilkes Booth, the actor who shot Lincoln; Conger later handed him Booth's diary, which they delivered to Stanton on 26 April.
In February 1867, before a congressional committee, Baker testified that the diary was no longer as it had been, and that sixteen or eighteen leaves had been cut out after it was handed over. He also admitted he had had it only a very short time. Conger testified that some pages were already missing when he carried it. Two members of the committee wrote that Baker might not have told the truth in a single thing.
Baker died in July 1868; his death certificate gave spinal meningitis, and a claim that Stanton poisoned him has no supporting document. His wartime case files survive at the National Archives. No trace has been found of his personal papers, or of the records of the questioning he ran in April 1865.
[Report #200] WHO. 'Col. L. C. Baker, head of the National Detective Police' (
archive.org). A 2022 profile: 'he rose to become the head of the federal intelligence service for the Union during the Civil War.' (
militaryimagesmagazine-digital.com) The title was his own: 'He also objected to not having been given a formal title — so he invented his own. He sometimes referred to himself as “Special Provost Marshall” or “Chief of the National Detective Police Department.”' (
militaryimagesmagazine-digital.com) The U.S. Secret Service: 'Lafayette Baker and Alan Pinkerton also served in the War Department' (
secretservice.gov); such wartime services 'are not the United States Secret Service formed within the Treasury Department on July 5, 1865.' (
secretservice.gov)
BEFORE THE SHOT. 'The War Department also issued orders for Baker to report to New York City on a limited mission to round up army deserters —effectively banishing him.' (
militaryimagesmagazine-digital.com) 'The secretary made the retaliatory move after discovering Baker had tapped his own telegraph lines on suspicion of corruption.' (
militaryimagesmagazine-digital.com)
THE MANHUNT. 'At three-twenty on the afternoon of Saturday, April 15th, this telegram had left the War Department' (
archive.org): 'Come here immediately and see if you can find the murderers of the President.' (
archive.org) Arrival, two tellings: 'arrived in Washington on Sun-day morning, April 16th' (
archive.org); and 'He arrived in Washington in the afternoon, and reported to Stanton for duty.' (
militaryimagesmagazine-digital.com) Both held. 'On 24 April, Colonel Baker placed 1st Lt. Edward P. Doherty and his detachment of twenty-five soldiers of the 16th Regiment Cavalry, New York State Volunteers, under the control of detective Everton J. Conger' (
history.army.mil). Booth's diary: 'He also handed over Booth’s diary, and other personal effects from both men.' (
militaryimagesmagazine-digital.com) Baker met the boat and 'took custody of Herold and other prisoners suspected of being part of the conspiracy.' (
militaryimagesmagazine-digital.com)
1867 TESTIMONY ON THE DIARY. 'On February 7th, upon examining the book, Colonel Baker testified that in his opinion it was not then in the condition in which it had been when Conger and he delivered it to Stanton on the afternoon of April 26th, 1865.' (
archive.org) 'he believed that at one place six-teen or eighteen leaves had been cut out since the book was handed over to the Secretary.' (
archive.org) 'He admitted that he had had the book in his possession but "a very short time"' (
archive.org). Against that, Conger: 'Aboard the steamer, when coming from Belle Plain to Washington on April 26th, 1865, he had had ample opportunity to inspect Booth's so-called diary' (
archive.org). 'A few leaves were missing then: "There were some out and I think the same."' (
archive.org) 'The Judge Advocate General (Holt) told the Committee on April 2nd:' (
archive.org) 'There was nothing in the diary which I could conceive would be testimony against any human being, or for any one except Booth him-self' (
archive.org). Both held. On his credibility: 'Two Democrats on the House Committee summed up Baker’s performance: “It is doubtful whether [Baker] has in any one thing told the truth, even by accident.”' (
militaryimagesmagazine-digital.com)
DEATH. 'In the spring of 1868, he contracted typhoid fever and died in the early morning of July 3. He was 42. Baker’s death certificate listed spinal meningitis as the cause. Conspiracy theorists claimed Stanton poisoned him to prevent the leaking of salacious state secrets.' (
militaryimagesmagazine-digital.com) The poisoning claim: held, no document found.
PAPERS. 'Case Files of Investigations by Levi C. Turner and Lafayette C. Baker, 1861-1866. M797. 137 rolls.' (
archives.gov) 'The index and case files are part of the series of records known as the "Turner-Baker papers," and they are in Record Group 94, Records of the Adjutant General's Office, 1780's-1917.' (
archives.gov) 'The Baker case files, containing fewer papers, include reports submitted by private persons and government officials relating to suspicious persons and alleged subversive activity, and correspondence.' (
archives.gov) His book: 'the highly inflated 704-page History of the United States Secret Service.' (
militaryimagesmagazine-digital.com)
HELD. Whether Baker's personal papers or his bureau's April 1865 interrogation records survive. Not found (Oct 2026); would settle: a National Archives finding aid for them, or the Turner-Baker case files (M797) read for April 1865.
THE OCTOBER 2026 RESEARCH REPORT SAID 'the eighteen missing pages excised from Booth’s diary prior to its introduction in the 1867 Surratt trial'; its source gives Baker's estimate of 'six-teen or eighteen leaves' (
archive.org), told to the House Judiciary Committee.