As the detectives continued to piece together the puzzle of Marcus' murder, they realized that they needed to find any physical evidence that could tie a suspect to the crime.
They began by searching the library for clues, looking for any fingerprints, hair or fibers that could provide a lead. But despite their best efforts, they came up empty-handed.
The detectives were starting to get frustrated and felt like they were hitting a brick wall. They had come so far in the investigation, but they still didn't have much concrete evidence to go on.
But then, they received a tip from a witness who had seen a suspicious-looking man lurking near the library on the night of the murder. The detectives eagerly went to question the witness, hoping that they would finally get a break in the case.
As they listened to the witness's story, the detectives couldn't believe their luck. The witness had noticed a man leaving the library with a strange object in his hand, and they had even been able to provide a description of the man.
The detectives quickly put out a description of the suspect to the rest of the police force, hoping that they could finally catch Marcus' killer.
As they waited for any new leads, the detectives felt the pressure mounting. They knew that solving this case would require all their skills and experience as detectives, and they were determined to see it through to the end.