NYPD officers arrested the neighbor suspected of killing Susan Trott in her Upper West Side apartment earlier this month, taking 24-year-old Anya Johnston into custody on Wednesday afternoon. She has been charged with murder and burglary.

Just before 5 a.m. on Sunday, October 21st, police responded to a welfare check requested by one of Trott's colleagues after days of radio silence. Upon arrival, they found a trail of blood leading from the living room to her bedroom, where the 70-year-old was lying on the floor with her throat slashed. Investigators noted no signs of forced entry, and both the guest log and building security footage suggested no one had come to visit Trott. Authorities quickly concluded that "all the pieces of that puzzle are in that building," as Chief of Detectives Dermont Shea put it last week, and focused their attentions on a "female person of interest."

No motive has been named, but Trott's friends have speculated that consistently high tensions with her neighbors may have played a role. Trott's habit of scattering bird seed for pigeons reportedly attracted rats to the block, which others in her building did not appreciate. She and her neighbors also clashed over dog etiquette, with the building board getting involved and conflict apparently boiling over into a physical altercation on at least one occasion, when another resident shoved Trott.

Police confirmed to Gothamist that Johnston has been in a psychiatric facility since the 21st, but could not confirm reports that she had a history of mental illness, which translated to unpredictable behavior when she stopped taking her medication.

Trott had lived in her apartment since the 1980s, and was an established advertising freelancer with an eccentric reputation in her neighborhood. She could often be seen wheeling her aging bulldog around in a baby carriage, or tending to the pigeons in nearby Riverside Park. It's not presently clear, however, what series of events led to her murder.