Last Saturday in the late afternoon, I left home to attend the funeral of a dear uncle who had died aged 92. I took the train, as I often do, from Tulse Hill train station, in South London with my seven-year-old son.
He insisted on going into the local shops to buy snacks to eat along the way. With crisps and sweets in hand we headed to the station and caught the 17:08 train.
Less than an hour later, a young man was murdered, stabbed to death, by the exact same row of shops where my son had just been skipping through the aisles looking for sweet treats.
