Read the Autopsy Report carefully.

Examine the Evidence Collection Form for Evidence #8132-8134 carefully.

The Autopsy Report says Evelyn was strangled by a ligature approximately 1cm in width and had red fibers under her fingernails (which suggests she was tugging at whatever was strangling her).

Evelyn was strangled by something that's composed of red fibers and about 1cm wide.

A lanyard with Evelyn's DNA on it was found near the crime scene (Evidence #8134). This lanyard is red and about 1cm wide.

The murder weapon is a red lanyard (Evidence #8134).