Elementary

From her initial location, the suspect took a bus, followed by a ferry. She then took a taxi, transferred to another taxi, and took a two-leg train journey to a financial institution, before taking 2 more taxis.

The suspect was observed attempting to perpetuate a medieval family curse by murdering a firstborn child. She departed by bus.

The suspect then impersonated a dentist, allowing her to induce an idiosyncratic reaction in a patient. She fled the scene of the crime by taking a sequence of 2 taxi rides.

After becoming involved in two overlapping love triangles on an island, the suspect committed a murder and framed her rival, leaving via a chain of 3 taxi rides.

The suspect then planted poison in a decanter of port to kill an abusive husband, inadvertently implicating his wife. She then took 2 taxi rides. Although she was then at a train station with a royal name, she chose instead to take a bus.

The suspect’s next crime – impersonating a doctor to give a lethal injection – was revealed because the victim scrawled his means of death on a newspaper. However, by the time it was discovered the perpetrator was 4 bus rides away.

In order to cover up her earlier crimes, the suspect placed poison in a water glass on a woman's bedside table, who mentioned a window as she died. She departed by train, then transferred to a taxi.

The suspect then poisoned her family’s fig paste sandwiches, which she was able to survive eating because she’d built up an immunity. She left the scene of the crime by a sequence of 2 taxis, passing behind a gallery.

Her solicitor then revealed a confession letter stating that the suspect had earlier murdered her mother. However, her father gave instructions only to reveal this fact upon news of future crimes, such as theft and impersonating a doctor. She evaded capture by taking a taxi, bus, then 2 taxis.

The suspect next arranged for a minor poisoning involving the herbs in a stuffed duck, concealing her subsequent murder with a similar substance. Finding that she had already visited everywhere reachable in one step from her current location, she then took a taxi  back to where she’d just come from, the only time on her journey she ever re-visited a location. She then took another taxi, a bus, a train, and finally a chain of 5 taxis that crossed at least one small body of water.

The suspect’s next victim tried to ask for an antidote, but the servants thought he was ranting about a "pile of carp". Meanwhile, the suspect was taking 2 taxis, then 2 trains  (with an intermediate stop at the corner of a park), then another taxi.

The suspect was observed poisoning some sprinkles, then leaving by a sequence of 2 taxis.

Although she, too, drank the laced tea she killed her next victims with, the suspect survived by inducing vomiting with a similarly-named compound from a bottle with a torn label. She made her escape by taxi and then transferred to a southeasterly-bound bus.

The suspect then murdered her son by sneaking pills into his after-dinner chocolates. After committing this final crime, she left by bus, transferred to another bus, and then prepared to take a train back to her original starting location.