Character mistake: Frank implies that Joe is the oldest child, but he was born in 1977 (1x22), Erin in 1975 (6x07), and Danny 1973 (2x17). Erin also claims she wasn't born yet when the murder of Henry's friend took place in 1977 but she would have been about two years old.
Character mistake: Sergeant Gormley is promoted to Lieutenant in the previous episode. In this episode he is referred to as Sergeant Gormley by Commissioner Reagan and Deputy Commissioner Garrett Moore at least twice.
Character mistake: In this episode, Garrett says that "Nom de Guere" means pen name. It means war name. Nom de Plume means pen name and Garrett is supposed to be an expert in his field.
Character mistake: Throughout the episode they refer to the victim owning a "cement" company. In fact it was a concrete company. Although the terms cement and concrete often are used interchangeably, cement is actually an ingredient of concrete. Concrete is basically a mixture of aggregates and paste. The aggregates are sand and gravel or crushed stone; the paste is water and portland cement. (00:00:05 - 00:35:50)
Answer: It is the lapel pin worn by members of the NYPD Honor Legion.
The lapel pin is on Danny but not Biaz, why? Also, Baker, Sid, Frank &Garrett wear one. Significance? Are they all the same?
Is the P.C.'s pin different than a legion pin? What are the symbols and their meaning?
I think it may be Masonic?
But why would the mayor wear one?