<P> Erin is divorced from John `` Jack '' Boyle ( Peter Hermann ) , a criminal defense attorney , whom she met when they were 19 . In `` Old Wounds '' , she finally changes her name from Erin Reagan - Boyle back to Erin Reagan . Since her divorce , Erin has had a few romantic interests . She and her boss , District Attorney Charles Rosselini ( Bobby Cannavale ) , flirted with each other and even shared a kiss after a date , but nothing ever came of it mainly due to Erin 's reluctance with the idea of dating her boss . In 2011 , she met Jacob Krystal ( Fred Weller ) at an art gallery ; she later learned that he was an art thief who returned once - stolen works to their rightful owners , and he left town . In 2013 , after being shot in a courtroom hostage situation , she started up a fling with her ex-husband Jack but broke up when they started getting serious again ( lest he break her heart again , or their daughter find out that they were once again `` hooking up '' ) . In 2014 , she met Robert McCoy , a defense attorney , on a speed - date , and the two became romantically involved until he was appointed interim District Attorney , at which point she said she ca n't sleep with her boss . </P>
<P> Erin is divorced from John `` Jack '' Boyle ( Peter Hermann ) , a criminal defense attorney , whom she met when they were 19 . In `` Old Wounds '' , she finally changes her name from Erin Reagan - Boyle back to Erin Reagan . Since her divorce , Erin has had a few romantic interests . She and her boss , District Attorney Charles Rosselini ( Bobby Cannavale ) , flirted with each other and even shared a kiss after a date , but nothing ever came of it mainly due to Erin 's reluctance with the idea of dating her boss . In 2011 , she met Jacob Krystal ( Fred Weller ) at an art gallery ; she later learned that he was an art thief who returned once - stolen works to their rightful owners , and he left town . In 2013 , after being shot in a courtroom hostage situation , she started up a fling with her ex-husband Jack but broke up when they started getting serious again ( lest he break her heart again , or their daughter find out that they were once again `` hooking up '' ) . In 2014 , she met Robert McCoy , a defense attorney , on a speed - date , and the two became romantically involved until he was appointed interim District Attorney , at which point she said she ca n't sleep with her boss . </P>
who is erin reagan 's boss on blue bloods
who is erin reagan 's boss on blue bloods
Charles Rosselini
Charles Rosselini