If you want details, a pair of female authors from Toronto (reportedly the safest city in North America?) wrote Safe Cities: Guidelines for Planning, Design and Management.  Here are some of their recommendations for safe cities, which are essentially ‘eyes on the street’ fundamentals:

- Retail street frontages (encourages street life);
- Restaurants/venues that stay open late;
- Outdoor seating; street entertainers and vendors;
- People-attracting food services;
- Mixed-income housing (creating a diversity of residents who frequent the streets at a diversity of hours);
- Pedestrian-friendly streets;
- Late-night transit hours;
- Housing above stores (built-in neighborhood watch);
- Upper-story windows and balconies overlooking the street;
- Street-front buildings built up to a continuous setback line to eliminate ‘hiding places’ and blindspots.

It’s also important to concentrate activity on the main pedestrian traffic corridors, just like the North End in Boston.