Part II research from book

In 1984, Billie Sol Estes told a grand jury investigating the 1961 shooting death of Henry Marshall, an official with the Department of Agriculture, that Mac Wallace was his murderer. Estes, a long-time conman who served two prison terms for his crimes, said that Marshall possessed information linking Estes's fraudulent schemes to a heavily funded political slush fund run by LBJ. According to Estes, he and Johnson discussed the need to stop Marshall from making their illegal ties public. In exchange for immunity from prosecution, Estes was also prepared to provide the Department of Justice information of eight killings orchestrated by Johnson, including the assassination. He claimed that Wallace persuaded Jack Ruby to recruit Oswald and that Wallace fired a shot that struck Kennedy.

Barr McClellan, author of “Blood, Money & Power: How LBJ Killed JFK,” reiterated many of Estes's claims in 2003 stating that Johnson, Wallace, Estes and Cliff Carter were responsible for the death of Marshall. According to McClellan, Wallace fired one shot at Kennedy from the sixth floor then ran and escaped. He stated that fingerprints and an eyewitness placed Wallace in that location and that Wallace could be seen as a "shadowy figure" in photos of the building. In their 2003 obituary of Estes, the New York Times wrote that none of Estes's claims against LBJ were backed by evidence. McClellan was a lawyer with the law firm in Austin that handled LBJ's secret financial empire before and after he became president.

Marshall had been asked to investigate the activities of Billie Sol Estes and discovered that over a two-year period, Estes had purchased 3,200 acres of cotton allotments from 116 different farmers. Estes sent his lawyer, John P. Dennison, to meet Marshall in Robertson County. At the meeting in January 1961, Marshall told Dennison that Estes was clearly involved in a "scheme or device to buy allotments, and will not be approved, and prosecution will follow if this operation is ever used." Marshall was then offered a new post at headquarters. He assumed that Estes had friends in high places and that they wanted him removed from the field office in Robertson County. A week after the meeting between Marshall and Dennison, A. B. Foster, manager of Billie Sol Enterprises, wrote to Clifton C. Carter, a close aide to Johnson, telling him about the problems that Marshall was causing the company. On June 3, 1961, Marshall was found dead on his farm by the side of his Chevy Fleetside pickup truck. His rifle lay beside him. He had been shot five times with his own rifle. He had a lame arm. Soon after County Sheriff Howard Stegall arrived, he decreed that Marshall had committed suicide. No pictures were taken of the crime scene, no blood samples were taken of the stains on the truck (the truck was washed and waxed the following day), no check for fingerprints were made on the rifle or pickup. Marshall was beaten so badly one eyeball was hanging from its socket

Marshall's wife and brother refused to believe he had committed suicide and posted a $2,000 reward for information leading to a murder conviction. The undertaker, Manley Jones, also reported: "To me it looked like murder. I just do not believe a man could shoot himself like that." The undertaker's son, Raymond Jones, later said his daddy said Judge Farmer told him he was going to put suicide on the death certificate because the sheriff told him to.

Sybil hired an attorney, W. S. Barron, in order to persuade the Robertson County authorities to change the ruling on Marshall's cause of death. One man who did believe that Marshall had been murdered was Texas Ranger Clint Peoples. He had reported to Col. Homer Garrison, director of the Texas Department of Public Safety, that it "would have been utterly impossible for Mr. Marshall to have taken his own life." Peoples also interviewed Nolan Griffin, a gas station attendant in Robertson County. Griffin claimed that on the day of Marshall's death, he had been asked by a stranger for directions to Marshall's farm. A Texas Ranger artist, Thadd Johnson, drew a facial sketch based on a description given by Griffin. Peoples eventually came to the conclusion that this man was Wallace, the convicted murderer of John Kinser. In the spring of 1962, Estes was arrested by the Federal Bureau of Investigation on fraud and conspiracy charges. Soon afterwards it was disclosed by the Secretary of Agriculture, Orville L. Freeman, that Marshall had been a key figure in the investigation into the illegal activities of Estes. As a result, the Robertson County grand jury ordered that the body of Marshall should be exhumed and an autopsy performed. After eight hours of examination, Dr. Joseph A. Jachimczyk confirmed that Marshall had not committed suicide.

On April 4, 1962, George Krutilek, Estes’s chief accountant, was found dead. Despite a severe bruise on Krutilek's head, the coroner decided that he had also committed suicide. The next day, Estes, and three business associates, were indicted by a federal grand jury on 57 counts of fraud. Two of these men, Harold Orr and Coleman Wade, later died in suspicious circumstances. At the time it was said they committed suicide but later Estes was to claim that both men were murdered by Wallace in order to protect the political career of Johnson. It was eventually discovered that three officials of the Agricultural Adjustment Administration in Washington had received bribes from Billie Sol Estes. Red Jacobs, Jim Ralph and Bill Morris were eventually removed from their jobs. However, further disclosures suggested that the Secretary of Agriculture might be involved in the scam. In September 1961, Billie Sol Estes had been fined $42,000 for illegal cotton allotments. Two months later, Freeman appointed Estes to the National Cotton Advisory Board.

Tommy G. McWilliams, the FBI agent in charge of the Marshall investigation, came to the conclusion that Marshall had indeed committed suicide. He wrote: "My theory was that he shot himself and then realized he wasn't dead." He then claimed that he then tried to kill himself by inhaling carbon monoxide from the exhaust pipe of his truck. McWilliams claimed that Marshall had used his shirt to make a hood over the exhaust pipe. Jachimczyk discovered a 15 percent carbon monoxide concentration in Marshall's body. Even J. Edgar Hoover was not impressed with this theory. He wrote on May 21, 1962: "I just can't understand how one can fire five shots at himself." The Robertson County grand jury continued to investigate the death of Marshall. However, some observers were disturbed by the news that grand jury member, Pryse Metcalfe, was dominating proceedings. Metcalfe was County Sheriff Howard Stegall's son-in-law. On June 1, 1962, the Dallas Morning News reported that Kennedy had "taken a personal interest in the mysterious death of Marshall. As a result, the story said, Robert Kennedy "has ordered the FBI to step up its investigation of the case." In June 1962, Billie Sol Estes, appeared before the grand jury. He was accompanied by John Cofer, a lawyer who represented Johnson when he was accused of ballot-rigging when elected to the Senate in 1948 and Mac Wallace when he was charged with the murder of John Kinser. Billie Sol Estes spent almost two hours before the grand jury, but he invoked the Texas version of the Fifth Amendment and refused to answer most questions on grounds that he might incriminate himself. Despite the evidence presented by Jachimczyk, the grand jury agreed with McWilliams. It ruled that after considering all the known evidence, the jury considers it "inconclusive to substantiate a definite decision at this time, or to overrule any decision heretofore made." Later, it was disclosed that some jury members believed that Marshall had been murdered. Ralph McKinney blamed Pryse Metcalfe for this decision. "Pryse was as strong in the support of the suicide verdict as anyone I have ever seen in my life, and I think he used every influence he possibly could against the members of the grand jury to be sure it came out with a suicide verdict."

Billie Sol Estes was released from prison in December 1983. Three months later he appeared before the Robertson County grand jury. He confessed that Marshall was murdered because it was feared he would "blow the whistle" on the cotton allotment scam. Billie Sol Estes claimed that Marshall was murdered on the orders of LBJ, who was afraid that his own role in this scam would become public knowledge. According to Estes, Clifton C. Carter, Johnson's long-term aide, had ordered Marshall to approve 138 cotton allotment transfers. Billie Sol Estes also told the grand jury that he met Carter and Wallace at his home in Pecos after Marshall was killed. Wallace described how he waited for Marshall at his farm. He planned to kill him and make it appear as if Marshall committed suicide by carbon monoxide poisoning. However, Marshall fought back and he was forced to shoot him with his own rifle. He quoted Carter as saying that Wallace "sure did botch it up." Johnson was now forced to use his influence to get the authorities in Texas to cover up the murder.

The grand jury did change the verdict on the death of Marshall from suicide to death by gunshot.