Pentagram

A pentagram is a five-pointed star. One is used in Small Favor.

Description
The pentagram is a five-pointed star, whose center forms a pentagon. It constitutes a symbol of power, drawn and employed in different ways according to its purpose; most often to isolate or contain an entity. The magical energy required to operate it depends on its size.

Small Favor
In Small Favor, Harry Dresden investigates a burning building with its face blownoff at the request of Murphy. Murphy notices that the rear of the building smells of Hellfire, and suspects magical involvement. Harry finds a sigil painted in blood and looking similar to a pentacle. Harry points out how the sigil has the five points of the star go outside the circle and that on his pentacle that he wears, the points only touch the outer circle. Harry says that it's uncomfortably like a combination of a pentacle and an anarchy symbol. — Magic unrestrained. Looking around he discovers that the sigil is only one of five reflective points with energy source coming from a different location. A beam came in from somewhere else: a whole lot of heat energy. — The beam streamed from one reflector to the next melting holes through the building. The reflectors formed the beam into one huge pentagram at ground level. One other weird thing about it, was that there was no trace of the magic when there should have been a lot of it. Like they wiped their magic prints clean.

"A Fistful of Warlocks"
In "A Fistful of Warlocks", Heinrich Kemmler, Grevane and Alexander Page use a pentagram to reanimate the zombies they use in the attack to Dodge City's prison.