Oswald was born at the old French Hospital in New Orleans, Louisiana, on October 18, 1939, to Robert Edward Lee Oswald Sr. (1896–1939) and Marguerite Frances Claverie (1907–1981). Robert Oswald was a distant cousin of Confederate general Robert E. Lee and served in the Marines during World War I. Robert died of a heart attack two months before Lee was born. Lee’s elder brother Robert Jr. (1934–2017) was also a former Marine. Through Marguerite’s first marriage to Edward John Pic Jr., Lee and Robert Jr. were the half-brothers of Air Force veteran John Edward Pic (1932–2000).

In 1944, Marguerite moved the family from New Orleans to Dallas, Texas. Oswald entered the first grade in 1945 and over the next half-dozen years attended several different schools in the Dallas and Fort Worth areas through the sixth grade. Oswald took an IQ test in the fourth grade and scored 103; “on achievement tests in [grades 4 to 6], he twice did best in reading and twice did worst in spelling.”

As a child, Oswald was described as withdrawn and temperamental by several people who knew him. When Oswald was 12 in August 1952, his mother took him to New York City where they lived for a short time with Oswald’s half-brother, John. Oswald and his mother were later asked to leave after an argument in which Oswald allegedly struck his mother and threatened John’s wife with a pocket knife.

When Lee returned to school for the 1953 Fall semester, his disciplinary problems continued. When Oswald failed to cooperate with school authorities, they sought a court order to remove him from his mother’s care so he could be placed into a home for boys to complete his education. This was postponed, perhaps partially because his behavior abruptly improved. Before the New York family court system could address their case, the Oswalds left New York in January 1954, and returned to New Orleans.

Oswald completed the eighth and ninth grades in New Orleans. He entered the 10th grade in 1955 but quit school after one month. After leaving school, Oswald worked for several months as an office clerk and messenger in New Orleans. In July 1956, Oswald’s mother moved the family to Fort Worth, Texas, and Oswald re-enrolled in the 10th grade for the September session at Arlington Heights High School in Fort Worth. A few weeks later in October, Oswald quit school at age 17 to join the Marines; he never earned a high school diploma. By this point, he had resided at 22 locations and attended 12 schools.

As a teenager in 1955, Oswald attended Civil Air Patrol meetings in New Orleans. Fellow cadets recalled him attending C.A.P. meetings “three or four” times, or “10 or 12 times” over a one- or two-month period.

Oswald enlisted in the United States Marine Corps on October 24, 1956, just a week after his seventeenth birthday; because of his age, his brother Robert Jr. was required to sign as his legal guardian. Oswald also named his mother and his half-brother John as beneficiaries. Oswald idolized his older brother Robert Jr., and wore his Marine Corps ring. John Pic (Oswald’s half-brother) testified to the Warren Commission that Oswald’s enlistment was motivated by wanting “to get from out and under … the yoke of oppression from my mother”.

Like all marines, Oswald was trained and tested in shooting. In December 1956, he scored 212, which was slightly above the requirements for the designation of sharpshooter. In May 1959 he scored 191, which reduced his rating to marksman.

Slightly built, Oswald was nicknamed Ozzie Rabbit after the cartoon character; he was also called Oswaldskovich because he espoused pro-Soviet sentiments. In November 1958, Oswald transferred back to El Toro where his unit’s function “was to serveil [sic] for aircraft, but basically to train both enlisted men and officers for later assignment overseas”. An officer there said that Oswald was a “very competent” crew chief and was “brighter than most people.”

While Oswald was in the Marines, he taught himself rudimentary Russian. Although this was an unusual endeavor, on February 25, 1959, he was invited to take a Marine proficiency exam in written and spoken Russian. His level at the time was rated “poor” in understanding spoken Russian, though he fared rather reasonably for a Marine private at the time in reading and writing. On September 11, 1959, he received a hardship discharge from active service, claiming his mother needed care. He was placed on the United States Marine Corps Reserve.

Oswald traveled to the Soviet Union just before he turned 20 in October 1959. He had taught himself Russian and saved $1,500 of his Marine Corps salary (equivalent to $10,500 in 2019). Oswald spent two days with his mother in Fort Worth, then embarked by ship on September 20 from New Orleans to Le Havre, France, and immediately traveled to the United Kingdom. Arriving in Southampton on October 9, he told officials he had $700 and planned to stay for one week before proceeding to a school in Switzerland. However, on the same day, he flew to Helsinki. In Helsinki, he checked-in at the Hotel Torni, room 309, then moved to another Hotel Klaus Kurki, room 429. He was issued a Soviet visa on October 14. Oswald left Helsinki by train on the following day, crossed the Soviet border at Vainikkala, and arrived in Moscow on October 16. His visa, valid only for a week, was due to expire on October 21.

On October 31, Oswald appeared at the United States embassy in Moscow and declared a desire to renounce his U.S. citizenship. “I have made up my mind,” he said; “I’m through.” He told the U.S. embassy interviewing officer, Richard Edward Snyder, that “he had been a radar operator in the Marine Corps and that he had voluntarily stated to unnamed Soviet officials that as a Soviet citizen he would make known to them such information concerning the Marine Corps and his specialty as he possessed. He intimated that he might know something of special interest.” Such statements led to Oswald’s hardship/honorable military reserve discharge being changed to undesirable. The Associated Press story of the defection of a former U.S. Marine to the Soviet Union was reported on the front pages of some newspapers in 1959.

German was invited to Oswald’s apartment for the first time on October 18, 1960, his twenty-first birthday. According to German, a quarrel ensued when a friend of Oswald brought another woman to the gathering, making it apparent to her that he had been intimate with other women. Oswald’s writings indicate that he had four to five sexual encounters with the woman over the following two weeks. German said she began to stop trusting Oswald after she learned in October 1960 that he had been seeing other women. According to German, Oswald showed up with a gift of chocolates at her family’s house on the evening of December 31, 1960, and spent New Year’s Eve with them. She stated that they had earlier quarreled about New Year’s Eve plans.

In March 1961, Oswald met Marina Prusakova (b. 1941), a 19-year-old pharmacology student; they married six weeks later. The Oswalds’ first child, June, was born on February 15, 1962. On May 24, 1962, Oswald and Marina applied at the U.S. Embassy in Moscow for documents that enabled her to immigrate to the U.S. On June 1, the U.S. Embassy gave Oswald a repatriation loan of $435.71. Oswald, Marina, and their infant daughter left for the United States, where they received less attention from the press than Oswald expected.

General Walker was an outspoken anti-communist, segregationist, and member of the John Birch Society. In 1961, Walker had been relieved of his command of the 24th Division of the U.S. Army in West Germany for distributing right-wing literature to his troops. Walker’s later actions in opposition to racial integration at the University of Mississippi led to his arrest on insurrection, seditious conspiracy, and other charges. He was temporarily held in a mental institution on orders from President Kennedy’s brother, Attorney General Robert F. Kennedy, but a grand jury declined to indict him.

In July 1962, Oswald was hired by the Leslie Welding Company in Dallas; he disliked the work and quit after three months. On October 12, he started working for the graphic-arts firm of Jaggars-Chiles-Stovall as a photoprint trainee. A fellow employee at Jaggars-Chiles-Stovall testified that Oswald’s rudeness at his new job was such that fights threatened to break out, and that he once saw Oswald reading a Russian-language publication. Oswald was fired in the first week of April 1963.

In March 1963, Oswald used the alias “A. Hidell” to make a mail-order purchase of a secondhand 6.5 mm caliber Carcano rifle for $29.95. He also purchased a .38 Smith & Wesson Model 10 revolver by the same method. The Warren Commission concluded that Oswald attempted to kill retired U.S. Major General Edwin Walker on April 10, 1963, and that Oswald fired the Carcano rifle at Walker through a window from less than 100 feet (30 m) away as Walker sat at a desk in his Dallas home. The bullet struck the window-frame and Walker’s only injuries were bullet fragments to the forearm. The United States House Select Committee on Assassinations stated that the “evidence strongly suggested” that Oswald carried out the shooting.

George de Mohrenschildt testified that he “knew that Oswald disliked General Walker.” Regarding this, de Mohrenschildt and his wife Jeanne recalled an incident that occurred the weekend following the Walker assassination attempt. The de Mohrenschildts testified that on April 14, 1963, just before Easter Sunday, they were visiting the Oswalds at their new apartment and had brought them a toy Easter bunny to give to their child. As Oswald’s wife Marina was showing Jeanne around the apartment, they discovered Oswald’s rifle standing upright, leaning against the wall inside a closet. Jeanne told George that Oswald had a rifle, and George joked to Oswald, “Were you the one who took a pot-shot at General Walker?” When asked about Oswald’s reaction to this question, George de Mohrenschildt told the Warren Commission that Oswald “smiled at that.” When George’s wife Jeanne was asked about Oswald’s reaction, she said, “I didn’t notice anything”; she continued, “we started laughing our heads off, big joke, big George’s joke.” Jeanne de Mohrenschildt testified that this was the last time she or her husband ever saw the Oswalds.

Oswald returned to New Orleans on April 24, 1963. Marina’s friend Ruth Paine drove her by car from Dallas to join Oswald in New Orleans the following month. On May 10, Oswald was hired by the Reily Coffee Company as a machinery greaser. He was fired in July “because his work was not satisfactory and because he spent too much time loitering in Adrian Alba’s garage next door, where he read rifle and hunting magazines”.

Marina’s friend Ruth Paine transported Marina and her child by car from New Orleans to the Paine home in Irving, Texas, near Dallas, on September 23, 1963. Oswald stayed in New Orleans at least two more days to collect a $33 unemployment check. It is uncertain when he left New Orleans; he is next known to have boarded a bus in Houston on September 26 — bound for the Mexican border, rather than Dallas — and to have told other bus passengers that he planned to travel to Cuba via Mexico. He arrived in Mexico City on September 27, where he applied for a transit visa at the Cuban Embassy, claiming he wanted to visit Cuba on his way to the Soviet Union. The Cuban embassy officials insisted Oswald would need Soviet approval, but he was unable to get prompt co-operation from the Soviet embassy. CIA documents note Oswald spoke “terrible hardly recognizable Russian” during his meetings with Cuban and Soviet officials.

On October 2, 1963, Oswald left Mexico City by bus and arrived in Dallas the next day. Ruth Paine said that her neighbor told her on October 14 about a job opening at the Texas School Book Depository, where her neighbor’s brother, Wesley Frazier, worked. Mrs. Paine informed Oswald, who was interviewed at the depository and was hired there on October 16 as a $1.25 an hour minimum wage order filler. Oswald’s supervisor, Roy S. Truly (1907–1985), said that Oswald “did a good day’s work” and was an above-average employee. During the week, Oswald stayed in a Dallas rooming house under the name “O. H. Lee”, but he spent his weekends with Marina at the Paine home in Irving. Oswald did not drive a car, but he commuted to and from Dallas on Mondays and Fridays with his co-worker Wesley Frazier. On October 20 (a month before the assassination), the Oswalds’ second daughter, Audrey, was born.

Photos of Oswald holding the rifle that was later determined to be the murder weapon are an important piece of evidence linking Oswald to the crime. The photos were uncovered with other possessions belonging to Oswald in the garage of Ruth Paine in Irving, Texas, on November 24, 1963. Marina Oswald told the Warren Commission that around March 31, 1963, she had taken pictures of Oswald as he posed with a Carcano rifle, a holstered pistol, and two Marxist newspapers — The Militant and The Worker. The pictures were shown to Oswald after his arrest, but he insisted that they were forgeries.

A network television pool camera was broadcasting live to cover the transfer; millions of people watching on NBC witnessed the shooting as it happened and on other networks within minutes afterward. In 1964, Robert H. Jackson of the Dallas Times Herald was awarded the Pulitzer Prize for Photography for his image of the murder of Lee Harvey Oswald by Jack Ruby.

In 1964, Marina testified before the Warren Commission that she had taken one and only one version of the two known versions of two poses of Oswald, at Oswald’s request using his camera — testimony she reaffirmed repeatedly over the decades. These photos were labelled CE 133-A and CE 133-B. CE 133-A shows the rifle in Oswald’s left hand and newspapers in front of his chest in the other, while the rifle is held with the right hand in CE 133-B. The Carcano in the images had markings matching those on the rifle found in the Book Depository after the assassination. Oswald’s mother testified that on the day after the assassination she and Marina destroyed another photograph with Oswald holding the rifle with both hands over his head, with “To my daughter June” written on it.

Oswald was never prosecuted because he was murdered two days after the assassination. In March 1967, New Orleans District Attorney Jim Garrison arrested and charged New Orleans businessman Clay Shaw with conspiring to assassinate President Kennedy, with the help of Oswald, David Ferrie, and others. Garrison believed that the men were part of an arms smuggling ring supplying weapons to the anti-Castro Cubans in a conspiracy with elements of the CIA to kill Kennedy. The trial of Clay Shaw began in January 1969 in Orleans Parish Criminal Court. The jury acquitted Shaw.

In 1968, the Ramsey Clark Panel examined various photographs, X-ray films, documents, and other evidence. It concluded that Kennedy was struck by two bullets fired from above and behind him: one of which traversed the base of the neck on the right side without striking bone, and the other of which entered the skull from behind and destroyed its right side.

Ruby later said he had been distraught over Kennedy’s death and that his motive for killing Oswald was “saving Mrs. Kennedy the discomfiture of coming back to trial”. Others have hypothesized that Ruby was part of a conspiracy. G. Robert Blakey, chief counsel for the House Select Committee on Assassinations from 1977 to 1979, said: “The most plausible explanation for the murder of Oswald by Jack Ruby was that Ruby had stalked him on behalf of organized crime, trying to reach him on at least three occasions in the forty-eight hours before he silenced him forever.”

The HSCA obtained another first-generation print (from CE 133-A) on April 1, 1977, from the widow of George de Mohrenschildt. The words “Hunter of fascists — ha ha ha!” written in block Russian were on the back. Also in English were added in script: “To my friend George, Lee Oswald, 5/IV/63 [April 5, 1963].” Handwriting experts for the HSCA concluded the English inscription and signature were by Oswald. After two original photos, one negative and one first-generation copy had been found, the Senate Intelligence Committee located (in 1976) a third backyard photo (CE 133-C) showing Oswald with newspapers held away from his body in his right hand.

In 1979, after a review of the evidence and of prior investigations, the United States House Select Committee on Assassinations (HSCA) largely concurred with the Warren Commission and was preparing to issue a finding that Oswald had acted alone in killing Kennedy. However, late in the Committee’s proceedings a dictabelt recording was introduced, purportedly recording sounds heard in Dealey Plaza before, during and after the shots. After an analysis by the firm Bolt, Beranek and Newman appeared to indicate more than three gunshots, the HSCA revised its findings to assert a “high probability that two gunmen fired” at Kennedy and that Kennedy “was probably assassinated as the result of a conspiracy.” Although the Committee was “unable to identify the other gunman or the extent of the conspiracy,” it made a number of further findings regarding the likelihood that particular groups, named in the findings, were involved. Four of the twelve members of the HSCA dissented from this conclusion.

Oswald’s original tombstone, which gave his full name, birth date, and death date, was stolen; officials replaced it with a marker simply inscribed Oswald. His mother’s body was buried beside his in 1981.

A claim that a look-alike Russian agent was buried in place of Oswald led to the body’s exhumation on October 4, 1981. Dental records confirmed it was Oswald. The remains were reburied in a new coffin because of water damage to the original.

In 1982, a panel of twelve scientists appointed by the National Academy of Sciences, including Nobel laureates Norman Ramsey and Luis Alvarez, unanimously concluded that the acoustic evidence submitted to the HSCA was “seriously flawed”, was recorded after the shots, and did not indicate additional gunshots. Their conclusions were published in the journal Science.

Several films have fictionalized a trial of Oswald, depicting what may have happened had Ruby not killed Oswald. The Trial of Lee Harvey Oswald (1964); The Trial of Lee Harvey Oswald (1977); and On Trial: Lee Harvey Oswald (1986) have imagined such a trial. In 1988, a 21-hour unscripted mock trial was held on television, argued by lawyers before a judge, with unscripted testimony from surviving witnesses to the events surrounding the assassination; the jury returned a verdict of guilty. In 1992 the American Bar Association conducted two mock Oswald trials. The first trial ended in a hung jury. In the second trial the jury acquitted Oswald.

German was still a resident of Minsk in 1993. She was interviewed by Mailer for his 1995 biography, Oswald’s Tale: An American Mystery. Mailer reported that German was a teacher at that time, living with and caring for her daughter and granddaughter. Savodnik also interviewed her for his 2013 book, The Interloper: Lee Harvey Oswald Inside the Soviet Union. As of 2015, German lived in Acre, Israel.

In a 2001 article in the journal Science & Justice, D.B. Thomas wrote that the NAS investigation was itself flawed. He concluded with a 96.3 percent certainty that at least two gunmen fired at President Kennedy and that at least one shot came from the grassy knoll. In 2005, Thomas’s conclusions were rebutted in the same journal. Ralph Linsker and several members of the original NAS team reanalyzed the timings of the recordings and reaffirmed the earlier conclusion of the NAS report that the alleged shot sounds were recorded approximately one minute after the assassination. In 2010, D.B. Thomas challenged the 2005 Science & Justice article and restated his conclusion that there were at least two gunmen.

These photos, widely recognized as some of the most significant evidence against Oswald, have been subjected to rigorous analysis. Photographic experts consulted by the HSCA concluded they were genuine, answering twenty-one points raised by critics. Marina Oswald has always maintained she took the photos herself, and the 1963 de Mohrenschildt print bearing Oswald’s signature clearly indicate they existed before the assassination. Nonetheless, some continue to contest their authenticity. In 2009, after digitally analyzing the photograph of Oswald holding the rifle and paper, computer scientist Hany Farid concluded that the photo “almost certainly was not altered”.

In 2010, Miller Funeral Home employed a Los Angeles auction house to sell the original coffin to an anonymous bidder for $87,468. The sale was halted after Oswald’s brother Robert (1934–2017) sued to reclaim the coffin. In 2015, a district judge in Tarrant County, Texas ruled that the funeral home intentionally concealed the existence of the coffin from Robert Oswald, who had originally purchased it and believed that it had been discarded after the exhumation, and ordered it returned to Robert Oswald along with damages equal to the sale price. Robert Oswald’s attorney stated that the coffin would likely be destroyed “as soon as possible.”

From approximately June 1960 to February 1961, Oswald was in a personal relationship with a Belarusian woman, Ella German (Belarusian: Эла Герман, a co-worker at the factory (born 1937). She has lived most of her life in Minsk, the capital of Belarus (until 1992 part of the Soviet Union); in 2013 she was living in the Israeli town of Acre.

Some critics have not accepted the conclusions of the Warren Commission and have proposed several other theories, such as that Oswald conspired with others, or was not involved at all and was framed. A Gallup Poll taken in mid-November 2013, showed 61% believed that Kennedy was killed as a result of conspiracy, and only 30% thought Oswald acted alone.

According to a CIA document released in 2017, it is possible Oswald was trying to get the necessary documents from the embassies to make a quick escape to the Soviet Union after the assassination.