Model Jury Instructions on Homicide list of principal revisions

The list of principal 2026 revisions to the Model Jury Instructions on Homicide.

List of principal revisions

1. The instruction on criminal responsibility is updated to reflect revisions from Commonwealth v. Dunphe, 485 Mass. 871 (2020), clarifying that a lack of criminal responsibility defense is not foreclosed where long-term drug use caused the defendant’s mental disease or defect. (Criminal Responsibility, pp. 6-12).
2. The joint venture instruction is modified in light of Commonwealth v. Sun, 490 Mass. 196 (2022), clarifying that to withdraw from or abandon a joint venture, there must be an appreciable interval between the withdrawal or abandonment and the crime. (Joint Venture, p. 22).
3. The joint venture instruction is supplemented to clarify that joint venturers need not be tried together, and that joint venture liability does not depend on the outcome of any other co-venturer's case. (Joint Venture, p. 23).
4. The joint venture instruction is supplemented to clarify that, where two or more defendants are tried together on both theories of individual and joint venture liability, one may be acquitted while the other is convicted as a joint venturer, or both may be acquitted, or both may be convicted. The instruction further clarifies that the fact that defendants are on trial together is not evidence that there is any connection between them and is not evidence of their guilt. (Joint Venture, pp.23-24).
5. The self-defense instruction is supplemented to clarify that a defendant may have actually believed that he was in immediate danger of serious bodily harm or death whether or not he suffered from a mental impairment or consumed alcohol or drugs, but that the jury may consider such evidence in determining whether the Commonwealth has proved that he lacked such a belief. (Self-Defense, pp. 34-35).
6. The self-defense instruction is updated to reflect revisions from Commonwealth v. Souza, 492 Mass. 615 (2023), which more concisely and understandably explain how a jury may consider so-called Adjutant evidence (i.e., evidence of the deceased's [and a third party acting together with the deceased's] past violent conduct). (Self-Defense, pp. 40-41).
7. The self-defense instruction is updated to provide a transferred intent self-defense instruction as set forth in the appendix to Commonwealth v. Santana-Rodriguez, 496 Mass. 693 (2025). (Self-Defense, pp. 49-53).
8. Use of the term “victim” is deleted throughout the main text of the instruction and, in most instances, is replaced with the more neutral term “deceased.”
9. The term “prong(s)” is no longer used when discussing the three different ways of proving the intent element of murder in the first degree with extreme atrocity or cruelty.  Instead, the instructions refer to the three “ways” in which the intent element can be proved. (Murder With Extreme Atrocity or Cruelty, pp. 62-64).
10. The instruction on murder in the first degree with extreme atrocity or cruelty is updated to clarify that a defendant may have the requisite intent even if he suffered from a mental impairment or consumed alcohol or drugs, but that the jury may consider such evidence in determining whether the Commonwealth has proved that element. (Murder With Extreme Atrocity or Cruelty, p. 66).
11. The instruction on murder in the first degree with extreme atrocity or cruelty is updated based on Commonwealth v. Castillo, 485 Mass. 852 (2020), which revised the so-called Cunneen factors that must be considered in deciding whether a defendant caused a death with extreme atrocity or cruelty.  The instruction further clarifies that a murder committed by a single blow may be extremely cruel or atrocious where there is evidence of one or more of those factors. (Murder With Extreme Atrocity or Cruelty, pp. 67-69).
12. The instruction on first-degree murder with extreme atrocity or cruelty is updated to clarify that a defendant may have committed a killing with extreme atrocity or cruelty even if he suffered from a mental impairment or consumed alcohol or drugs, but that the jury may consider such evidence in determining whether the Commonwealth has proved that element. (Murder With Extreme Atrocity or Cruelty, p. 70).
13. The instruction on felony-murder in the first degree is updated to clarify that the jury must unanimously agree on which felony, or felonies, the defendant committed to convict under the theory of felony murder. (Felony-Murder in the First Degree, p. 75).
14. The term “prong(s)” is no longer used when discussing the three different ways of proving the intent element of felony-murder in the first-degree. Instead, the instructions refer to the three “ways” in which the intent element can be proved. (Felony-Murder in the First Degree, pp. 79-82).
15. The instruction on felony-murder in the first-degree is updated to clarify that, if the jury has a reasonable doubt as to whether the death was accidental, because the death was caused by a negligent, careless, or mistaken act of the defendant, or resulted from a cause separate from the defendant's conduct, the jury may not find that the Commonwealth has proven the intent element. (Felony-Murder in the First Degree, p. 82). 

Date published:	March 30, 2026