His first brush with the law was in 1935 when he was charged with breach of the peace for which he was fined $20. Then in April of the same year he stole two purses from the Vogue Beauty Shop. Since the value of the purses exceeded $25, he was convicted of a felony, grand larceny, and sentenced to a year in the Kentucky State Penitentiary at Eddyville. He arrived there on June 1, 1935. His physical showed him to be 5 feet, 4 3/8 inches (1.64 meters) tall and to weigh 128 pounds (58 kg). On December 1, 1935 he was paroled.

After removing a screen from her window, he entered the room, waking her. Bethea then strangled Edwards and violently raped her. After she was unconscious, he searched for valuables and stole several of her rings. In the process he removed his own black celluloid prison ring, but failed to retrieve it. He left the bedroom and hid the stolen jewels in a barn not far from the house.

The crime was discovered late that morning after the Smith family noticed they had not heard Edwards stirring in her room. They feared she might have been ill and knocked on the door of her room attempting to rouse her. Finding the door locked with a skeleton key from the inside, they contacted a neighbor, Robert Richardson, hoping he could help. Richardson managed to knock the key free, but another skeleton key would not unlock the door. Smith then obtained a ladder and climbed into the room through the transom, over the door. It was then that they discovered Edwards was dead.

The Smiths alerted Dr. George Barr while he was attending a service at the local United Methodist Church. Dr. Barr realized there was little he could do and summoned the local coroner, Delbert Glenn, who also attended the same church. The Smiths also called the Owensboro police. Officers found the room was otherwise tidy, but there were muddy footprints everywhere. Coroner Glenn also found a celluloid prison ring, which Bethea, in his drunken state, had inadvertently left behind in the room.

Throughout the next four days, the police searched for the murderer. By late Sunday afternoon, the police already suspected Rainey Bethea after several residents of Owensboro stated that they had previously seen Bethea wearing the ring. Since Bethea had a criminal record, the police were able to use what was then a new identification technique - fingerprints - to establish that Bethea had recently touched items inside the bedroom.

On the Wednesday, Burt "Red" Figgins was working on the bank of the Ohio River when he observed Bethea lying under some bushes. Figgins asked Bethea what he was doing, and Bethea responded he was "cooling off." Figgins then reported this sighting to his supervisor, Will Faith, and asked him to call the police. By the time Faith had returned to the spot on the river bank, Bethea had moved to the nearby Koll's Grocery. Faith followed him and then found a policeman in the drugstore, but when they searched for Bethea, he again eluded capture.

Once incarcerated at the Jefferson County Jail in Louisville, Bethea made a second confession, this time before Robert M. Morton, a notary public, and George H. Koper, a reporter for The Courier-Journal. Officials requested the presence of the notary and the reporter anticipating that Bethea, or someone else, might accuse them of coercing his confession.

On June 12, Bethea made a third confession and told the Captain of the Guards where he had hidden the jewelry. Owensboro police searched a barn in Owensboro and found the jewelry, just where Bethea said he had left it.

Under Kentucky law, the grand jury could not convene until June 22, and the prosecutor decided to charge Bethea solely with rape. The reason was, under the Kentucky law, if a punishment of death was given for murder and robbery, it was to be carried out by electrocution in the state penitentiary at Eddyville. However, rape could be punished by public hanging in the county seat where the crime occurred. To avoid a potential legal dilemma as to whether Bethea would be hanged or electrocuted, the prosecutor elected to charge Bethea only with the crime of rape. So Bethea was never charged with the remaining crimes of murder, robbery, burglary, or theft. After only an hour and forty minutes, the grand jury returned an indictment, charging Bethea with rape.

On June 25, officers returned Bethea to Owensboro for the trial. Bethea was unhelpful to his state-appointed attorneys — William L. Wilson, William W. "Bill" Kirtley, Carroll Byron, and C. W. Wells, Jr.. He said that a Clyde Maddox would provide an alibi, but on interviewing Maddox, Maddox claimed he did not even know Bethea. In the end they subpoenaed four witnesses — Maddox, Ladd Moorman, Willie Johnson (whom Bethea had implicated as an accomplice in his second confession) and Allen McDaniel. Only the first three were served, because the sheriff's office could not find a person named Allen McDaniel.

On the night before the trial, Bethea announced to his lawyers that he wanted to plead guilty, and he did so the next day at the start of the trial. The prosecutor, however, still presented the state's case to the jury, since the jury would decide his sentence and since the prosecutor was asking for the death penalty. The first twelve of 111 people called for the jury were selected. At the time, only white men served on American juries.

During his opening statement, the Commonwealth's Attorney Herman Birkhead said, "This is one of the most dastardly, beastly, cowardly crimes ever committed in Daviess County. Justice demands and the Commonwealth will ask and expect a verdict of the death penalty by hanging."

After questioning 21 witnesses, the prosecution closed its case-in-chief. The defense did not call any witnesses nor cross-examine the witnesses who testified for the prosecution. After a closing statement by the prosecutor, the judge instructed the jury that, since Bethea had pled guilty, their only task was to "…fix his punishment, at confinement in the penitentiary for not less that ten years nor more than twenty years, or at death." After only four and a half minutes of deliberation, the jury returned with a sentence — death by hanging. Bethea was then quickly removed from the courthouse and returned to the Jefferson County Jail.

Back in Louisville, Bethea acquired five new black lawyers — Charles Ewbank Tucker, Stephen A. Burnley, Charles W. Anderson, Jr., Harry E. Bonaparte, and R. Everett Ray. They worked without pay to challenge the sentence, something they saw as their ethical duty for the indigent defendant. On July 10 they filed a motion for a new trial. The judge summarily denied this on the grounds that under Section 273 of the Kentucky Code of Practice in Criminal Cases, a motion for a new trial had to have been received before the end of the court's term, which had ended on July 4.

They then attempted to appeal to the Kentucky Court of Appeals, which was also not in session. On July 29, Justice Gus Thomas returned to Frankfort, Kentucky where he heard the motion orally. Justice Thomas refused to permit the appeal to be filed on the grounds that the trial court record was incomplete, which only included the judge's ruling. Although it may seem that Bethea's lawyers were incompetent, they knew the appeal would be denied, and this was only a formality in order to exhaust state court remedies before they filed a petition for writ of habeas corpus in a federal court.

Among the hundreds of letters that Sheriff Thompson received after it came to public attention she would perform the hanging was one from Arthur L. Hash, a former Louisville police officer, who offered his services free of charge to perform the execution. Thompson quickly decided to accept this offer. He only asked that she not make his name public.

Thompson also received a letter from the Chief Deputy United States Marshal for the District of Indiana telling her of a farmer from Epworth, Illinois, named G. Phil Hanna, who had assisted with hangings across the country. Bethea's hanging would be the 70th which Hanna had supervised. He himself never pulled the trigger that released the trapdoor, and the only thing he asked for in return was the weapon used in the crime. Hanna developed his interest in the "art" of hanging after he witnessed the botched execution of Fred Beheme at McCleansboro, Illinois, in 1896, which had resulted in the condemned man suffering greatly. As such, Hanna saw it as his main task to provide whatever assistance he could to ensure a quick, painless death. Hanna did not always succeed in this endeavor — during the hanging of James Johnson on March 26, 1920, the rope broke and Johnson fell to the ground and was severely injured. Hanna had to descend the steps, carry the injured Johnson back to the scaffold, and proceed with his execution.

On August 6, the Governor of Kentucky Albert Chandler signed Bethea's execution warrant and set the execution for sunrise on August 14. However, Sheriff Thompson requested the governor to issue a revised death warrant because the original warrant specified that the hanging would take place in the courthouse yard, where the county, at significant expense, had recently planted new shrubs and flowers. Chandler was out-of-state, so Lieutenant Governor Keen Johnson signed a second death warrant, moving the location of the hanging from the courthouse yard to an empty lot near the county garage.

Rainey Bethea's last meal consisted of fried chicken, pork chops, mashed potatoes, pickled cucumbers, cornbread, lemon pie, and ice cream, which he ate at 4:00 p.m. on August 13 in Louisville. At about 1:00 a.m. Daviess County deputy sheriffs transported Bethea from Louisville to Owensboro. At the jail, Hanna visited Bethea and instructed him to stand on the X that would be marked on the trapdoor.

It was estimated that a crowd of 20,000 people gathered to watch the execution, with thousands coming from out of town. Hash arrived drunk at the site, wearing a white suit and a white Panama hat. At this time, no one but he and Thompson knew he would be pulling the trigger.

Bethea left the Daviess County Jail at 5:21 a.m. and walked with two deputies to the scaffold. Within two minutes, he was at the base of the scaffold. Removing his shoes, he put on a new pair of socks. He ascended the steps and stood on the large X as instructed. He made no final statement to the waiting crowd. After making his final confession to Father Lammers, of the Cathedral of the Assumption Church in Louisville, the black hood was placed over his head, and three large straps placed around his ankles, thighs and arms and chest.

On January 17, 1938, Kentucky Senator William R. Attkisson of the 38th Senatorial District in Louisville, introduced Senate Bill 69, calling for the repeal the requirement from Section 1137 that death sentences for the crime of rape be conducted by hanging in the county seat where the crime was committed. Representative Charles W. Anderson, Jr., one of the attorneys who assisted Bethea in his post conviction relief motions, promoted the bill in the House of Representatives.

After both houses approved the bill on March 12, 1938, Governor Albert B. Chandler signed it into law, and it became effective on May 30, 1938. Chandler later expressed regret at having approved the repeal, claiming, "Our streets are no longer safe."

The last person to be legally hanged in Kentucky was Harold Van Venison, a thirty-three-year-old black singer, who was privately hanged in Covington on June 3, 1938. Van Venison was hanged on June 3, 1938, after the rape law had actually been repealed. Governor Chandler signed no death warrant in this case, and, for this reason, the hanging was conducted in violation of Section 297 of the Kentucky Code of Criminal Practice. Before the hanging, a legal question arose as to whether Van Venison should hang or be electrocuted, since the rape law requiring hanging had been repealed effective May 30, 1938.