In People v. Nelson (2008) 43 Cal.4th 1242, the California Supreme Court found strong justification for delay where the police suspected defendant of killing a young woman in 1976 but did not charge him with murder until 2002, when scientific advances led to development of DNA testing that matched defendant with crime scene evidence. (Nelson, supra, 43 Cal.4th at p. 1256.) The defendant in Nelson showed prejudice from the delay in prosecution but the California Supreme Court found no due process violation after balancing the demonstrated prejudice against the justification for the delay. The high court adopted the findings of the court of appeal on this point:"'The delay was not for the purpose of gaining an advantage over the defendant. Indeed, the record does not even establish prosecutorial negligence. The delay was the result of insufficient evidence to identify defendant as a suspect and the limits of forensic technology. When the forensic technology became available to identify defendant as a suspect and to establish his guilt, the prosecution proceeded with promptness. Without question, the justification for the delay outweighed defendant's showing of prejudice.'" (Id. at p. 1257.) In Nelson, the police suspected defendant of killing a young women in 1976 but did not charge him with murder until scientific advances led to development of DNA testing that matched defendant with crime scene evidence in 2002. (Id. at p. 1256.) The high court concluded:"'The delay was not for the purpose of gaining an advantage over the defendant. Indeed, the record does not even establish prosecutorial negligence. The delay was the result of insufficient evidence to identify defendant as a suspect and the limits of forensic technology. When the forensic technology became available to identify defendant as a suspect and to establish his guilt, the prosecution proceeded with promptness. Without question, the justification for the delay outweighed defendant's showing of prejudice.'" (Id. at p. 1257.) The court rejected the argument that the prosecution was negligent in failing to conduct the DNA comparison test sooner. The California Supreme Court stated:"Defendant argues that the DNA technology used here existed years before law enforcement agencies made the comparison in this case and that, therefore, the comparison could have, and should have, been made sooner than it actually was. Thus, he argues, the state's failure to make the comparison until 2002 was negligent. We disagree. A court may not find negligence by second-guessing how the state allocates its resources or how law enforcement agencies could have investigated a given case. . . . The difficulty in allocating scarce prosecutorial resources (as opposed to clearly intentional or negligent conduct) is a valid justification for delay . . . .'. It is not enough for a defendant to argue that if the prosecutorial agencies had made his or her case a higher priority or had done things a bit differently they would have solved the case sooner." (Id. at pp. 1256-1257.) In People v. Nelson (2008) the defendant challenged admission of DNA evidence on the ground the statistical method used to calculate the odds that the crime scene evidence could have come from someone else had not achieved general scientific acceptance under People v. Kelly (1992) and its progeny. (Nelson, at p. 1257.) The court summarized his argument thus: "Defendant agrees that using the product rule to calculate the random match probability makes sense when comparing one suspect's profile with the crime scene evidence because, as he explains, the random match probability 'estimates the chance that any single, random person drawn from the rele-vant population would have the same DNA profile as that of the unknown person whose DNA was found at the crime scene.' But he contends that a match made in a cold hit through a database search is different. He argues as follows: When a single suspect is compared to the crime scene evidence, 'the basic question ("What is the probability or chance that a person selected at random from the relevant population would have a DNA profile matching that of the evidentiary sample"), is appropriate because the authorities already have reason to suspect one particular person's DNA profile will match the evidence sample DNA profile before the two profiles are compared. But that same question presupposes the probability statistic involves a randomly-selected person. It thus cannot be posed in a "cold hit" case, for in such cases the only reason authorities have come to suspect one particular person is because they already know his DNA profile matches that of the crime scene evidence. In fact, they already compared the DNA profiles of tens of thousands (if not hundreds of thousands), of other persons, in order to find him. In other words, in a "cold hit" case the suspect is never "randomly" selected from the general population.' Thus, when a suspect is found by a search of a large DNA database, the chance of a coincidental match is increased because 'a single genetic profile (from the crime scene evidence) is compared to the very large number of profiles in these databases.'" (Id. at p. 1260.) The court first determined that use of the product rule to calculate the odds in a cold hit case was not a new scientific technique subject to the Kelly test, and that the product rule reliably shows what it purports to show, namely the rarity of the genetic profile in the population group. (Nelson, supra, 43 Cal.4th at pp. 1259-1260.) The court then addressed the question whether the odds calculated by the product rule were relevant, and thus admissible, in a cold hit case and determined that "although the product rule is not the only available method of statistical analysis in a cold hit case, it is relevant and thus admissible." (Id. at p. 1260.) The Nelson court concluded: "Although the product rule no longer represents the random match probability in a cold hit case, the Jenkins court ultimately agreed with the government's argument 'that regardless of the database search, the rarity statistic is still accurately calculated and appropriately considered in assessing the significance of a cold hit.... While a database search changes the probability of obtaining a match, it does not change how rare the existence of that specific profile is in society as a whole.... This rarity is ... both consistent and relevant regardless of the fact that the defendant's identification is the product of a database search.' "In a non-cold-hit case, we said that 'it is relevant for the jury to know that most persons of at least major portions of the general population could not have left the evidence samples.' We agree with other courts that have considered the question inter alia, Johnson and Jenkins that this remains true even when the suspect is first located through a database search. The database match probability ascertains the probability of a match from a given database. 'But the database is not on trial. Only the defendant is.' Thus, the question of how probable it is that the defendant, not the database, is the source of the crime scene DNA remains relevant. The rarity statistic addresses this question." (Nel-son, supra, 43 Cal.4th at pp. 1266-1267.) The California Supreme Court held that "negligent, as well as purposeful, delay in bringing charges may, when accompanied by a showing of prejudice, violate due process." (Nelson, supra, 43 Cal.4th at p. 1255.) The court observed that the United States Supreme Court had discussed the due process implications of investigative and prosecutorial delay on multiple occasions without ever having been called on to decide whether negligent conduct might implicate a defendant's due process rights. (Nelson, supra, 43 Cal.4th at pp. 1251-1253.) It concluded that because "the exact standard under the United States Constitution is not entirely settled, ... we can and will apply California law." (43 Cal.4th at p. 1251.) In Nelson, the defendant had been interviewed as a suspect in a 1976 murder, but was not charged until 2002, following DNA testing of semen stains found on the victim. (Nelson, supra, 43 Cal.4th at pp. 1248-1249.) Rejecting the defendant's claim that the 26-year delay in bringing charges violated his constitu-tional rights to a fair trial and due process, the court observed: "The police may have had some basis to suspect defendant of the crime shortly after it was committed in 1976. But law enforcement agencies did not fully solve this case until 2002, when a comparison of defendant's DNA with the crime scene evidence resulted in a match, i.e., until the cold hit showed that the evidence came from defendant. Only at that point did the prosecution believe it had sufficient evidence to charge defendant." (Id. at p. 1256.) The court emphasized that "'prosecutors are under no duty to file charges as soon as probable cause exists but before they are satisfied they will be able to establish the suspect's guilt beyond a reasonable doubt. ...'" (Ibid.) The California Supreme Court stated the following general standard for determining whether a defendant's due process rights were violated by precharging delay: "Although precharging delay does not implicate speedy trial rights, a defendant is not without recourse if the delay is unjustified and prejudicial. 'The right of due process protects a criminal defendant's interest in fair adjudication by preventing unjustified delays that weaken the defense through the dimming of memories, the death or disappearance of witnesses, and the loss or destruction of material physical evidence.' Accordingly, 'delay in prosecution that occurs before the accused is arrested or the complaint is filed may constitute a denial of the right to a fair trial and to due process of law under the state and federal Constitu-tions. A defendant seeking to dismiss a charge on this ground must demonstrate prejudice arising from the delay. The prosecution may offer justification for the delay, and the court considering a motion to dismiss balances the harm to the defendant against the justification for the delay.'" (Id. at p. 1250) Nelson also clarified the California standard for establishing a due process violation based on precharging delay. "Under California law, negligent, as well as purposeful, delay in bringing charges may, when accom-panied by a showing of prejudice, violate due process. This does not mean, however, that whether the delay was purposeful or negligent is irrelevant." (Nelson, supra, 43 Cal.4th at p. 1255.) "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.)