I saw the tail end of the Sparrowhawk as it went into the Ivy which clades our neighbour Derek's house. The Sparrows who live there screamed at this invasion of their home. Several minutes passed before the Hawk re-appeared, a single Sparrow floated to the ground below.
The Sparrowhawk flew into the Ash tree in the Sparrow garden then back to the first floor back extension roof of the house next door, around 15 feet away from where I was sitting on my first floor roof-terrace. There it sat, unconcerned by my presence the Sparrowhawk turned and looked at me without fear. After 3 or 4 minutes it flew off into the grounds of the flats behind my garden.
There was no sign of the fallen Sparrow.