Jennifer Love Hewitt previously starred in Criminal Minds season 10 as a leading cast member for one season and today's guest star for 9-1-1 in this episode A.J. Cook, who played the main character Jennifer 'JJ' Jareau in Criminal Minds both actresses reunited after seven years due to Hewitt's leave of absence for her second pregnancy.
The line "We have a piper down, I repeat a piper is down" is a quote from the movie So I Married An Axe Murderer (1993).
Beginning here, Jennifer Love Hewitt now sports a nose ring.