From Cost v. State, 417 Md. 360, 10 A.3d 184 (Ct. App. 2010):

Maryland recognizes some form of jury instructions regarding missing or destroyed evidence in both civil and the criminal contexts. In the civil context, we give a jury instruction for the "spoliation of evidence" where a party has destroyed or failed to produce evidence. The pattern jury instruction reads as follows:

The destruction of or the failure to preserve evidence by a party may give rise to an inference unfavorable to that party. If you find that the intent was to conceal the evidence, the destruction or failure to preserve must be inferred to indicate that the party believes that his or her case is weak and that he or she would not prevail if the evidence was preserved. If you find that the destruction or failure to preserve the evidence was negligent, you may, but are not required to, infer that the evidence, if preserved, would have been unfavorable to that party.

MPJI-CV 1:10. Such an instruction is designed to draw a jury's attention to a simple, straightforward premise: that "one does not ordinarily withhold evidence that is beneficial to one's case." Anderson v. Litzenberg, 115 Md. App. 549, 562, 694 A.2d 150, 156 (1997). The instruction does not require that a jury make an adverse inference in situations involving the spoliation of evidence; rather, it merely permits such an inference. ***

We have also recognized a "missing evidence" instruction in a criminal proceeding, though only against the defendant. The Maryland Criminal Pattern Jury Instructions ("MPJI-CR") include an instruction on "Concealment or Destruction of Evidence as Consciousness of Guilt[,]" which reads in part as follows:

Concealment or destruction of evidence is not enough by itself to establish guilt, but may be considered as evidence of guilt. Concealment or destruction of evidence may be motivated by a variety of factors, some of which are fully consistent with innocence.

You must first decide whether the defendant [concealed, destroyed, or attempted to conceal or destroy] evidence in this case. If you find that the defendant [did so] . . . then you must decide whether that conduct shows a consciousness of guilt.

MPJI-CR 3:26. We have held that "[c]onsciousness of guilt evidence . . . , including . . . destruction or concealment of evidence[,]" is significant because "the particular behavior provides clues to the [actor's] state of mind[.]" Decker v. State, 408 Md. 631, 640, 641, 971 A.2d 268, 274 (2009). This is hardly a novel concept; numerous commentators have expressed similar sentiments. Wigmore, for example, has explained the significance of the destruction of evidence as follows:

It has always been understood — the inference, indeed, is one of the simplest in human experience — that a party's falsehood or other fraud in the preparation and presentation of his cause, his fabrication or suppression of evidence by bribery or spoliation, and all similar conduct is receivable against him as an indication of his consciousness that his case is a weak or unfounded one; and from that consciousness may be inferred the fact itself of the cause's lack of truth and merit. The inference thus does not necessarily apply to any specific fact in the cause, but operates, indefinitely though strongly, against the whole mass of alleged facts constituting his cause.

2 John Henry Wigmore, Evidence in Trials at Common Law § 278 (Chadbourn rev. 1979) (emphasis deleted and footnote omitted).

Here we consider the distinct, though related, question of when a "missing evidence" instruction is required against the State in a criminal proceeding.

In a previous case, we have considered whether a defendant in a criminal case was entitled to a jury instruction regarding evidence that the State had failed to produce. See Patterson v. State, 356 Md. 677, 682, 741 A.2d 1119, 1121 (1999). ***

As we recognized in Patterson, the requirement that a defendant in a criminal proceeding show "bad faith" has its origin in Arizona v. Youngblood, 488 U.S. 51, 109 S.Ct. 333, 102 L. Ed. 2d 281 (1988). In Youngblood, a man was convicted for the rape of a young boy despite inconclusive scientific evidence. See Youngblood, 488 U.S. at 52-54, 109 S.Ct. at 333-35. One sample of the assailant's semen had not been refrigerated by the State, and expert testimony given at trial demonstrated that the defendant could have been exonerated if the evidence had been preserved. See id at 54, 109 S.Ct. at 335. After conviction, the Arizona Court of Appeals reversed, holding that the State had denied the defendant due process by failing to preserve the evidence. See id. The Supreme Court disagreed, holding that the Due Process clause was not violated when "there was no suggestion of bad faith on the part of the police." Id. at 58, 109 S.Ct. at 338. The specific holding of Youngblood is that the Due Process clause is not violated, and thus the charges should not be dismissed, where the defendant has failed to show bad faith by the State in failing to preserve evidence that could be subject to further tests. Since Youngblood, states have struggled to determine the scope of the "bad faith" requirement. ***

[W]e see an emerging consensus that a universal bad faith standard does not go far enough to adequately protect the rights of a person charged with a crime. The courts have seen the bad faith requirement as a potentially bottomless pit for a defendant's interest in a fair trial, and stepped back from the brink. ***

The evidence destroyed [in this case] while in State custody was highly relevant to Cost's case. A factual issue at trial was whether Brown was, indeed, stabbed, and whether the alleged stabbing caused significant bleeding, as Brown insisted. While Cost was able to shed doubt on Brown's claim through Brown's medical records, he was prevented from supporting his case with laboratory analysis of Brown's clothing, towel, sheets, and the red substance on the floor of Brown's cell. Such evidence might well have created reasonable doubt as to Cost's guilt. This missing evidence could not be considered cumulative, or tangential -- it goes to the heart of the case. We are persuaded that under these circumstances a "missing evidence" instruction, which would permit but not demand that the jury draw an inference that the missing evidence would be unfavorable to the State, should have been given. To be sure, even absent the instruction, Cost could argue that the State's case was weak without this evidence. But argument by counsel to the jury will naturally be imbued with a greater gravitas when it is supported by a instruction on the same point issued from the bench. As we have previously said, "a statement or instruction by the trial judge carries with it the imprimatur of a judge learned in the law, and therefore usually has more force and effect than if merely presented by counsel." Hardison v. State, 226 Md. 53, 62, 172 A.2d 407, 411 (1961).

***We hold that Cost was entitled to a jury instruction on the missing evidence because the State had destroyed highly relevant evidence in its custody that it normally would have retained and submitted to forensic examination.