The exact sequence of events becomes a little confused at this point, but we do know that Jackson was booked on suspicion of murder and locked in a police cell. Detectives Bulmer and Witte searched him there, stripping Jackson naked and finding two scratches on his right arm. One began just below the elbow and ran nearly three inches down towards his wrist. The second was much shorter, and made on the wrist itself. The detectives also found spots of blood on Jackson's undershirt, which he'd tried to wash away.
Police knew from the knife wounds on Pearl's own hand that she'd tried to fight her attacker off, and Jackson's scratches were just the kind a frightened girl might have inflicted with her fingernails. When they challenged him on this point, Jackson said he'd been bothered by insect bites a night or two ago, and given himself the marks while scratching away at these bites. Continuing their search, the detectives found two carriage tickets in Jackson's pockets, showing he'd recently crossed Cincinnati's Central Newport Bridge into Kentucky. There was nothing to suggest that particular journey had any sinister motive, but the tickets did show he'd lied when Caldwell asked him about visiting Newport.
Newspapers throughout Ohio and Kentucky were still going to town on the murder, and they all made the most of Jackson's arrest. In streets and saloons all over Cincinnati and Newport, angry men discussed what an evil bastard Jackson must be, and talked of lynching him. A Cincinnati shooting gallery placed a sign outside its door reading: "Put a bullet in Scott Jackson's brain, and win a 5-cent cigar". Inside, the owners had put up an effigy of Jackson for customers to shoot at, and this attraction did a brisk trade.
Police took the threats of violence against Jackson seriously, and thanked their lucky stars he was being held in Cincinnati rather than Newport, where the urge to lynch him was even more pronounced and the small jail much harder to defend. Jackson, too, seemed to think lynch mobs were a real possibility. Around midnight on Wednesday, he called Curren, the guard, over to him and said: "I want you to get a chair and sit in front of my cell all night".
"Are you afraid of getting lynched?" Curren replied.
"Well, never mind that. I prefer to be well-guarded whether I'm in danger or not."
Even with Cullen right in front of his cell, Jackson remained restless, rolling back and forth on his bunk, but unable to sleep. At about 2:00am, he approached Cullen again, and asked: "Hasn't Walling been arrested yet?"
The police knew that Jackson shared his Ninth Street room with another dental student named Alonzo Walling, but until now they'd had no reason to think Walling might have been involved in the case. "Why should he be arrested?" the puzzled Cullen asked. Jackson clammed up again at that point and refused to discuss Walling any further. When Cullen told his boss, Lieutenant Corbin, what the prisoner had said, Corbin went straight round to the boarding house and, by 3:30am on Thursday, Walling was in custody too.
Jackson and Walling first met at the dental school in Indianapolis, but knew each other only slightly there. They renewed their friendship in Cincinnati in October 1895, when Jackson was just starting his first term as a student in the city. Walking down West Ninth Street, he'd run into Walling outside McNevin's boarding house. Both men were now enrolled at Cincinnati's dental college and, on the strength of their old acquaintance, decided to share a room together at Mrs McNevin's.
Walling was about seven years younger than Jackson, and had none of his friend's luck, cunning or easy charm. His own father died when Walling was about five years old, leaving the boy and his mother no choice but to abandon their home in Mount Carmel, Indiana, and stay with various Ohio relatives instead. His mother worked and saved hard, and was able to move them to Greencastle in around 1890, where she began taking in boarders. Walling, then about 13 years old, started working as a glass blower to help support the family, but lost his job there after four years when the factory closed. With help from the rest of the family, his hard-pressed mother then managed to send him to Indianapolis dental school, where Jackson was already enrolled.
"Walling was the opposite of Jackson," one friend told the Post. "His mind was slow, his experience limited. He had a strong body, but lacked amiability. He was weak-willed and easily swayed by someone with a stronger mind." Reis describes him as "a stolid and morose character", who was "5 feet 8 inches tall, with dark hair and hazel eyes under heavy eyebrows that almost met."
Crim, McDermott and Plummer handed Wood over at the Central Police Station in City Hall as soon as they got back to Cincinnati on Thursday, February 6, where he was registered as a material witness and then released on bail and allowed to take a room at the city's Grand Hotel. Crim and McDermott went to search Jackson's accommodation at the boarding house, where they found a pair of lady's stockings stuffed behind his trunk and, inside that trunk, a lady's pocket book with a piece of gold chain inside.
The papers now had Walling's arrest to report too, and redoubled their coverage as a result. This fresh wave of stories produced two crucial witnesses from the city's taverns. The first to come forward was a saloon keeper called John Kugel, whose bar was on the corner of Ninth and Central, just a few blocks from both Jackson's boarding house and his new home in a City Hall cell. Kugel walked into City Clerk Vickers' office on Thursday and said he had a valise that Jackson had left in his bar for safe-keeping on Monday night. Vickers told him to go and fetch it quick.
Kugel returned a few minutes later carrying a tan-coloured leather bag, about 15 inches long, with handles rather than a shoulder strap. Vickers took the bag to Deitsch, who examined it, finding there was nothing inside but that the inner lining was badly stained with blood. "Deitsch closed the valise and asked Kugel who gave it to him," Barclay says. "Kugel said that, on Monday night, about eight o'clock, a young man with a blonde moustache walked into his place and asked him to take care of the valise, saying he would call for it the next day." But Jackson had never returned, which is why Kugel still had the bag.