Talking about how you make decisions to cross the road etc... is all very nice and well intentioned, but it's kind of a separate and nebulous issue. It's also the framing of all of this as individual responsibility. Yes, it's very good that more people take individual responsibility and scrutinise their behaviour, which will hopefully eventually lead to wider change, but it's not enough.
It's important to recognise it was not just a man who killed Sarah, but a police man, a man who has the uniform and carries the identity of the state. You can't solve this with more police on the streets, making more things a crime etc... They don't keep people safe on the streets now, and they aren't about to start.
What women experience in terms of harassment, abuse, violence etc... is horrific, and absolutely something that needs to be addressed much more significantly. However, that doesn't capture the full issue of this case, in which a police officer has likely abused their uniform/ID/authority in order to murder a young woman. There are a lot of important interventions which should be made for the safety of women, education, street lighting, transport infrastructure, affordable and safe public transport etc... but whilst these measures may increase the safety of people targeted by a random catcaller, assaulter or worse, they don't do anything to support someone who is approached by someone (a police officer) who knows they are above the law.