This is the old court house and police station in Greville Street, Prahran. Its style is described as Gothic Revival and I can see the Gothic for sure. It is a fine building. I am not able to immediately find out what it is now used for but possible it has a connection to the nearby Prahran Town Hall.
When I noticed the building, it struck me that in spite of its very typical Victorian bluestone foundations, it had a Sydney look about it. While I could ask why as a quiz question, I'll suggest that it the colour of the wall stone. Many Sydney buildings are built of light coloured sand stone and while I don't know if this building is sandstone, it is certainly unusually light for a Melbourne building.