A joinder is an alternative to filing a motion seeking relief on the same grounds as a motion filed by another party. It is efficient for the client and less work for the Court. The joinder asks the Court for the same relief already requested in another motion, but in the name of the joining party. A party can join the entirety of another party’s motion, join in certain arguments, or move on new relief while joining in part of another motion.
Joinders are usually short and simple. The point is to save everyone work when the arguments are already made and need no further argument. It is usually enough to state how the grounds for relief apply to the joining party.
Your papers. You will want to give notice of your joinder as you would for a motion, indicating that your client will seek the same relief based on the same grounds in the pending motion. Include a memorandum of points and authorities that explains why the Court knows the issues are the same.
Timing. Joinders have to be filed with the same notice as regular motions. See Barak v. Quisenberry Law Firm, 135 Cal. App. 4th 654, 660-662 (2006) (joinder allowed when timely filed).
Basis for Relief. Unless it is plainly obvious, the papers should include an explanation and/or evidence establishing that the joining party is entitled to relief. In particular, motions for summary judgement are typically not suitable for joinder, as the moving party bears the burden of showing that there are no disputed issues. However, even if the issues are identical, the party must file its own separate statement. See Village Nurseries, L.P. v. Greenbaum, 101 Cal. App. 4th 26, 46-47 (2002); Frazee v. Seely, 95 Cal. App. 4th 627, 636-37 (2002).
The amount of detail will vary with the circumstances. In a recent First Circuit case, the Court explained this:
While Federal Rule of Appellate Procedure 28(i) permits co-appellants to “adopt by reference a part of another’s brief,” as we have reminded litigants in the past, “[a]doption by reference cannot occur in a vacuum and the arguments must actually be transferable from the proponent’s to the adopter’s case.” United States v. Brown, 669 F.3d 10, 16 n. 5 (1st Cir. 2012). Therefore, where, as here, an appellant “offer[s] no explanation as to why [his co-appellant’s] arguments pertained to him,” such “textbook perfunctory” treatment waives the appellant’s attempts to adopt-by-reference his co-appellant’s arguments. Id. (emphasis omitted); see also United States v. Espinal–Almeida, 699 F.3d 588, 599 n. 9 (1st Cir. 2012) (a criminal defendant’s mere statement that he “joins in any and all other arguments raised by the other criminal co-defendants that are applicable to his case” is not sufficient (alterations omitted)).
U.S. v. Ramirez-Rivera, 800 F.2d 1, 12 n.1 (1st Cir. 2015).