What is the current state and federal constitutional test for determining whether a delay in bringing charges was justified?

meet his or her burden of showing prejudice, there is no need to determine whether the delay was justified." (People v. Abel (2012) 53 Cal.4th 891, 909.)

"The state and federal constitutional standards regarding what justifies delay differ. Regarding the federal constitutional standard, we have stated that '[a] claim based upon the federal Constitution also requires a showing that the delay was undertaken to gain a tactical advantage over the defendant.' " (People v. Nelson, supra, 43 Cal.4th at p. 1251.) Although "the exact standard under [the United States] Constitution is not entirely settled[,] [i]t is clear, however, that the law under the California Constitution is at least as favorable for [the] defendant in this regard as the law under the United States Constitution. Accordingly, we . . . apply California law." (Ibid.) "[U]nder California law, negligent, as well as purposeful, delay in bringing charges may, when accompanied by a showing of prejudice, violate due process." (Id. at p. 1255.) Thus, "whether the delay was negligent or purposeful is relevant to the balancing process. Purposeful delay to gain an advantage is totally unjustified, and a relatively weak showing of prejudice would suffice to tip the scales towards finding a due process violation. If the delay was merely negligent, a greater showing of prejudice would be required to establish a due process violation." (Id. at p. 1256.)