The revelation that the death was a consequence of a frantic attempt to steal the incriminating ledger had narrowed the field, but it had not solved the murder. Mr. Samson stood over Theressa, the weight of his gaze forcing the young man to confront the final, terrible truth.
"An accident is a sloppy occurrence, Theressa," Samson repeated, his voice low and firm. "A fall from the top of that sweeping staircase would have resulted in a body tumbling down the center line, impacting the lowest steps, perhaps the floor. But Mr. Walter's body was found to the left, near the wall, and the fatal trauma was on the back-left side of his head, suggesting impact with the sharp corner of the second riser on that side. The body was deliberately guided to that spot."
Samson walked over to the table and used his left hand to illustrate, tracing an arc with his finger. "If two people Chris and Walter were struggling at the top, and Walter slipped, the fall would have been down the middle. For him to be shunted to the left, towards the wall, required a final, decisive push, delivered with specific force and direction."
Theressa was shaking his head, tears streaming down his face. "Chris didn't push him! They were struggling. It was panic!"
"Panic, yes. But one person in that struggle knew exactly what they were doing, and possessed the precise physical capability to turn a slip into a fatal impact," Samson countered, his eyes shining with the excitement of final deduction. "Theressa, I am an eccentric man. People find my left-handedness unusual. It is a detail that always seems to stick in the minds of others."
He paused, letting the statement resonate. "Think back to the struggle. Chris, right-handed, was holding the ledger in one hand and the sash in the other. He was panicked. Walter was lunging for the ledger. Now, imagine yourself at the top of the stairs, trying to fend off a raging, silk-robed man. If you are right-handed, you would naturally use your dominant arm to push or block, likely leading to a fall down the center line."
Samson stepped back and then, with a sharp, fluid movement of his left arm, he demonstrated the action. He made a tight, inward sweep toward an imaginary wall.
"However, if the person struggling with Walter was left-handed, and they felt the man beginning to slip, an instinctive, forceful shove with their dominant left arm would turn Walter's momentum. It would propel his body, not straight down, but slightly inward and to the left, causing the specific trajectory that led to the left-sided impact on that second riser."
He waited for the realization to dawn on Theressa's face.
"Who in that struggle was left-handed, Theressa? Not Walter, who signed documents with his right hand. Not your father, who plays golf right-handed. Not Theodore, who writes with his right hand. Not your mother, Mrs. Walter, who signs checks with her right hand. But one of the two people at the top of the stairs with Walter one of the people with the ledger and the sash was left-handed."
Theressa's eyes widened in horror. "Chris…"
"The stepson," Samson concluded, nodding slowly. "The golden boy, the recipient of all of Walter's forced generosity. Chris, the quiet, polished one, whose dark-skinned hand I observed repeatedly making deliberate, left-handed gestures during our interview. His left-handedness is unusual, but perfectly suited to deliver the final, small, lethal push that turned an accident into a murder of calculated opportunity."
Samson continued, piecing together the final psychology of the act. "Chris had the strongest combination of motive and access. Theodore had the rage, but not the control. Eleanor had the lover, but not the direct access at that hour. Chris, however, was facing imminent financial ruin from his step-father, who knew about his mother's lover, and who was preparing to ruin Theressa's father his friend as well. It was a crisis for his entire fabricated life."
"Chris and Theressa go in for the ledger. The struggle begins. Walter sees his precious sash damaged the symbol of the honor he forced Chris to respect. Walter, consumed by rage, lunges. Chris, panicked but operating on years of bottled resentment, fends him off. Walter slips, but he's not clear of the edge. Then, Chris sees his opportunity. The end of his torment. A single, instinctive, left-handed shove, delivered with the precise knowledge that the railing and the corner of the stairs are there to assist him."
"It was Chris who said, 'You can't do this, Chris! It will ruin us both!'" Theressa corrected, tears now turning to shame.
Samson smiled faintly. "No, Theressa. You said that, as the right-handed boy, watching in horror as your friend the left-handed boy executed a deadly maneuver with practiced ease. Chris was never afraid of being ruined. He was only afraid of being caught."
Samson placed a call to Ms. Cynthia, instructing her to send an officer to retrieve Chris and the stolen ledger.
The confrontation was staged later that evening in the Mayor's office the very room where the mystery had begun. Mayor William, looking pale and thoroughly defeated, watched as Ms. Cynthia escorted Chris into the room. Chris still carried the veneer of polite distress, but his eyes were flat and cold.
Samson stood over the mahogany desk, flanked by the Mayor and Ms. Cynthia. He laid out the evidence: the stolen ledger (retrieved by the police), the gold-and-green thread, and the police photographs showing the exact trajectory of the body.
"Chris," Samson said, his voice ringing with authority. "We know everything. Theressa has confessed to the attempted robbery of the ledger, a robbery motivated by Walter's plan to ruin Mayor William and financially starve you. But he did not confess to murder. That distinction, my friend, belongs entirely to you."
Samson produced the gold-and-green thread. "This piece of Walter's pride was ripped away during the struggle at the top of the stairs. Walter, enraged, lunged at you. You were holding the ledger and trying to fend him off. He slipped."
"It was an accident," Chris repeated, his voice low and controlled.
"No," Samson countered, his dark skin gleaming under the harsh office light. "It was a left-handed murder of opportunity. The fall was guided to ensure Walter hit the sharp corner of the second riser, an action requiring a precise, inwardly directed thrust that could only be delivered by a dominant left arm."
Samson dramatically lifted his own left hand and pointed it at Chris. "You, Chris, were Walter's golden boy. But he was your tyrant. You hated his control and knew that if he survived, he would ruin your future and the man who was truly your friend, Theressa's father. In that moment of slip, you saw your chance. You turned his fall into an execution."
Chris listened, his eyes flickering between Samson's focused face and his own hands, which were now clenched tightly into fists. He knew the one detail, the one physical trait that set him apart, had betrayed him.
"You wouldn't understand," Chris finally said, the polished facade crumbling into bitter resentment. "He built a cage for all of us and locked it with his ego! I was going to be free! He deserved to lose his control—to lose his pride."
Chris turned and looked directly at the Mayor, whose political career was now in tatters due to his son's involvement in a robbery. "He was going to ruin your life, Mayor! He was going to take everything from everyone!"
Mayor William stared at the left-handed stepson, the realization that he was facing a cold-blooded killer mixed with the knowledge that his own political survival was tied to the exposure of Walter's crooked ledger.
Samson stepped between them. "The confession is noted, Chris. The cage is now open for some, and closed forever for you."