BBC News sometimes uses a widget with a list where each bullet is 'connected' by a line. This is how it works.

So, the line to the left..
is created using a :before pseudo-element on each <li>..
with no content, 2 pixels wide, red background color, and..
positioned absolutely relative to the list item.
The bullets are rendered using SVG which I tweaked from the BBC but are essentially just drawing circles.

See this pen for an extension of the concept placing the bullet SVGs into the CSS too. Credit.