MuSR / Who is the most likely murderer?

In the hushed silence of the library, Floyd lay dead with a shiv protruding from his chest, prompting Detective Winston to weave through the labyrinth of books and suspicion, targeting his primary suspects, Zara and Catherine.

After the news of Floyd's death, Winston found himself surrounded by books, cameras, and whispers. Libraries were supposed to bring tranquility, but now, this one seemed to echo with the whispers of a crime. The forensic team had found punctured wounds on Floyd's body, a mixture of peculiar cuts and punches, that were oddly similar to those that could be inflicted with a shiv; the kind that could easily be improvised with sharp tools. This had resulted in his untimely demise.

He had just visited Floyd's library, shifting through the catalogue of CCTV feed. It showed Zara entering the library during the day. She had a fairly regular routine, according to the library personnel. Winston also caught a glimpse of her re-emerging later, her steps were quick and purposeful. 

Winston kept his thoughts grounded, going through the notes he made during his interrogation session. Who was Zara, besides the latest burning face of the fashion industry? Her social media was a cascade of her embracing scissors, needles and other sharp filaments in her ostensible designs. Objects that, considering enough technique, can be reshaped into a dangerous weapon like a shiv.

He flipped through the photos of Zara's workspace. There was a toolkit - an array of sharp, glimmering instruments specifically designed for crafting fashion. They also gave Winston a hint of a chilling familiarity with the puncture evidence.

Later, Winston found himself in front of a small, quaint house. From here he could clearly see it, the neighbor's living room window faced directly onto Zara's driveway. The neighbor, a night owl of sorts, spent most of his time binge-watching on Netflix. He had always been proud of his knack for precision-perfect timing.

He had another reliable source too - Zara's older brother. Often, due to an insomniac streak, he would visit Zara at night to check up on her. Each time, he noticed the room light would go off, followed soon by the faint hum of her car starting. 

"Tell me again," Winston asked both of them in turn, "when did you hear Zara's car start?"

"Just after her room light went off," they iterated, almost in chorus, "like clockwork."

Evidently, Floyd the book lover's final day, a day spent around books, had an unexpected visitor - Zara. The pieces fell away like breadcrumbs leading into an obscure path. Winston knew this monumental work could unravel itself only with time. For now, it was time for the detective to take a coffee break, before immersing into the enigma once again.

After a long day of gathering information and different pieces of evidence, Winston found himself heading towards the residence of a pilot named Catherine. Floyd, the victim, was found dead in the library with obvious signs he was attacked with a sharp object, possibly a shiv. Detailed research unclosed particulars about Catherine's time in the military where she learned to use a unique blade like a shiv. Catherine admitted that after her military days, she continued to feel safer practicing using her shiv which she always carried with her.  This significant piece of information is what led Winston here, to question Catherine directly. 

"Good evening, Catherine," Winston began upon her opening the door, "I trust you were expecting me?" Catherine's slightly widened eyes suggested otherwise, but she still opened the door further, welcoming him inside. 

"I am sorry for the inconvenience, but I need to ask a few questions regarding Floyd."

"Floyd?" She asked. "What has happened?"

Winston said, "Our investigation revealed that he was continuously asking you for the money you owed him." He further added, “He was planning to take legal action if you didn’t pay, proof of which we found in his office."

Upon hearing this, Catherine responded, "Yes, he was putting me under a lot of pressure to pay back.” She then pointed towards her busy calendar placed on her desk and revealed, "We had a meeting scheduled today at the library to discuss the matter, it's right there in the calendar."

Confirming Floyd's attendance at the meeting Winston adds, "Yes, we've checked the library's sign-in book and confirmed that Floyd did check in for the meeting."

Catherine shrugged. "I was supposed to meet him there. About my debts to him."

"Your debts..?" Winston asked, raising an eyebrow. "Would you care to talk more about it?"

"Not much to say detective," shrugged Catherine, "I owed him money... wasn't able to pay."

"Why weren't you able to pay this debt?"

She sighed heavily with a far off gaze in her eyes as truth revealed itself. "I'd been missing a lot of mortgage payments. Had to sell my airplane. Just haven't been able to make ends meet..."

Winston shifted his gaze to a bag that sat on a nearby desk. Marked beside it were a few library books. Catherine followed Winston's gaze. "I took them from the library," she admitted. That would explain why her fingerprints were all over the books.

Winston smirked lightly. "And the librarian confirmed seeing you there, around the time of Floyd’s murder.”

With an unsettling chuckle, he switched the topic "I heard you were in the military?"

Catherine nodded. "Yes, I was."

"The military - where we learn a lot, including how to use a shiv I am assuming?”

Catherine chuckled lightly. "Well, yes. And as you can see," she pointed towards her bag on her desk, wherein upon casual inspection Winston found the shiv, "I never stopped practicing. It makes me feel safe to have it with me."

The shiv perfectly fit the description of the blade used in the murder of Floyd. It was the perfect weapon for a practiced hand to use quickly and quietly in a crowded library. 

But Winston merely nodded to himself as he jotted down a note or two. "You're full of surprises, Catherine."

They spent a couple more minutes talking aimlessly about life, the military, and Catherine's days in the air. But finally, Winston stood, getting ready to leave.

"I'll be back if I have more questions. Good evening Catherine."

As Winston drove away, his mind replayed back the facts he had collected throughout the day; Catherine's debts, her financial struggles, Floyd's continuous pressure for the money Catherine owed, Floyd's plan to take legal action, their planned meeting at the library, her continued practice with the blade, the missed mortgage payments, Catherine’s military background, the identified shiv in her bag, her bold admission of always feeling safer with her shiv and possibly most incriminating, the librarian’s testimony...

His job was merely about gathering the facts. The rest was for the law and the jury to decide.