In United States v. Guerrero, --- F.3d ---, No. 17-50384 (9th Cir. 2019), the Court held that the good cause requirement of Fed R. Crim. P 12(c)(3) -- and not the plain error standard -- continues to apply to suppression arguments raised for the first time on appeal.
Because the defendant cannot meet this standard he is out of luck.
Of note, is the new argument the defendant tried to raise: "He notes that California law requires
a driver to signal before making a turn only if another vehicle
on the road “may be affected by the movement.” Cal.
Vehicle Code § 22107; see People v. Carmona, 124 Cal.
Rptr. 3d 819, 823–25 (Ct. App. 2011). He asserts that the
government introduced insufficient evidence that the
driver’s alleged failure to signal could have impacted
another car on the road. See United States v. Caseres,
533 F.3d 1064, 1069 (9th Cir. 2008). Thus, he concludes,
even if the driver did not signal before turning, the officers
lacked a lawful basis for making the stop."
