This episode functions as a sort of origin story for Alonso, who in the flashbacks is presented as a member of the K-9 unit, eventually asking Hicks if there are any women in SWAT.
Deacon tells his daughter, Lila, that she was named after one of the victims of the 2013 shooting.
Shemar Moore and Meredith Monroe previously worked together on Criminal Minds.
There is a school in Columbia, Maryland called River Hill.
The SWAT uniforms shown in the 2013 flashbacks resemble the ones seen in the 2003 movie.