*1247**250The defendant was tried before a jury in the District Court for cruelty to animals in violation of G. L. c. 272, § 77. During the trial, one of the six jurors was excused from service for reasons unrelated to the case. After conducting a colloquy in which the judge informed the defendant of his right to a jury of six persons, the judge found that the defendant knowingly and voluntarily waived that right, and the trial continued with five jurors. The defendant was subsequently convicted. He unsuccessfully moved for a new trial, arguing that his waiver was invalid **251because it was not in writing pursuant to Mass. R. Crim. P. 19 (b), 378 Mass. 888 (1979) ( rule 19 [b] ). We transferred the defendant's appeal to this court on our own motion and conclude that a written waiver is unnecessary as long as the trial judge ensures, by way of a colloquy, that the defendant's decision to so proceed is made knowingly and voluntarily. We therefore affirm the denial of the defendant's motion for a new trial.
Facts and prior proceedings. The defendant was tried on one count of animal cruelty. During the lunch break prior to the close of evidence, a juror asked to be excused because of a death in his family. The trial judge granted the request, leaving a jury of five persons. See G. L. c. 218, § 26A. Defense counsel then notified the judge that the defendant wished to go forward with a five-person jury. The judge engaged in a colloquy with the defendant to ensure that the waiver of the full jury was knowing and voluntary.1 However, the *1248waiver was not in writing, and the Commonwealth never stated a position regarding the waiver.
The defendant filed a notice of appeal, and then submitted an unopposed motion for a new trial. The defendant's motion was denied without a hearing. The defendant appealed from the denial of that **252motion, and the two appeals were consolidated. We transferred the case sua sponte for review. **253Discussion. 1. Waiver of right to full jury. General Laws c. 234A, § 68, governs, among other things, the empanelment of jurors. It states in pertinent part:
"Nothing in this section shall prevent the court from rendering a valid judgment based upon a verdict rendered by fewer jurors than required under this section where all parties have by stipulation agreed to this procedure. Nothing in this section shall prevent the court from entering a valid judgment based upon a verdict rendered by fewer or more jurors than required under this section or based upon procedures other than that specified in this section where all parties have by stipulation agreed to such a number of jurors or to such procedures."
Rule 19 (b), which is the procedural rule that addresses proceeding with less than a full complement of jurors, states in part:
"If after jeopardy attaches there is at any time during the progress of a trial less than a full jury remaining, a defendant may waive his right to be tried by a full jury and request trial by the remaining jurors by signing a written waiver which shall be filed with the court."
The Commonwealth contends that notwithstanding rule 19 (b), because a written waiver is not statutorily required in order to **254proceed with fewer than the specified number of jurors, as long as the defendant waives this right knowingly and willingly, an oral waiver is valid. The defendant argues that his conviction should be reversed because the existing statute and rule should be read together to require both a stipulation by the parties pursuant to G. L. c. 234A, § 68, and a written waiver pursuant to rule 19 (b). We agree with the Commonwealth.
A review of the procedure to waive the right to a trial by jury is instructive. General Laws c. 263, § 6, provides: "Any defendant in a criminal case other than a capital case, whether begun by indictment or upon complaint, may, if he shall so elect, ... before a jury has been impanelled to try him ..., waive his right to trial by jury by signing a written waiver thereof and filing the same with the clerk of the court."
*1249See G. L. c. 218, § 26A ("Trial of criminal offenses in the Boston municipal court department and in the district court department shall be by a jury of six persons, unless the defendant files a written waiver and consent to be tried by the court without a jury"). The procedural rule corresponding to this statutory requirement, Mass. R. Crim. P. 19 (a), similarly calls for the waiver of the right to a jury trial to be in writing: "A case in which the defendant has the right to be tried by a jury shall be so tried unless the defendant waives a jury trial in writing with the approval of the court and files the waiver with the clerk ...."
We have recognized the requirement of a written jury waiver as a "legislative safeguard" designed "to create a moment of pause and reflection on the part of a defendant that is concomitant with signing one's name to a formal declaration relinquishing that right." Commonwealth v. Osborne, 445 Mass. 776, 780, 840 N.E.2d 544 (2006). Thus, the lack of a written waiver of a criminal defendant's right to a jury trial had been held to render the conviction of that defendant invalid. Id. at 781, 840 N.E.2d 544. See Commonwealth v. Wheeler, 42 Mass. App. Ct. 933, 934-935, 678 N.E.2d 168 (1997).
The defendant reasons that we similarly should enforce strictly the procedural rule requiring a written waiver of the right to a full complement of jurors. We disagree based on the legislative history of the statute and principles of statutory construction. Prior to the adoption of the rules of criminal procedure, waiver of the right to be tried by a full jury was governed by former G. L. c. 234, § 26A, and was required to be in writing.2 The rule was intended to reflect existing practice, as provided in the statute. See Reporter's **255Notes to Rule 19, Mass. Ann. Laws Court Rules, Rules of Criminal Procedure, at 1701 (LexisNexis 2018) ( rule 19 in accord with G. L. c. 234, § 26A ). However, in 1979, the Legislature repealed this statute and amended G. L. c. 263, § 6, to require waiver of a jury trial altogether to be in writing. See St. 1979, c. 344, §§ 9, 19. Three years later, the Legislature enacted G. L. c. 234A, § 68, which now addresses waiver of a full complement of jurors and requires only that "all parties have by stipulation agreed to this procedure." See St. 1982, c. 298, § 1.
Here, the Legislature reasonably could have recognized that there is a difference between choosing between a jury trial and a bench trial, where a defendant must decide whether to be tried by members of the community or by a single judge, and choosing between a trial by a full complement of jurors and a trial by somewhat less than a full jury. Cf. Commonwealth v. Hubbard, 457 Mass. 24, 28, 926 N.E.2d 1178 (2010) (in enacting G. L. c. 263, § 6, "[t]he Legislature reasonably could have decided that a written jury trial waiver is paramount in circumstances where ... a judge, instead of a jury, is to determine a defendant's guilt"). Moreover, "[w]here the Legislature has deleted ... language, apparently purposefully, the current *1250version of the statute cannot be interpreted to include the rejected requirement. Reading in language that the Legislature chose to remove ... violates basic principles of statutory construction and impermissibly interferes with the legislative function." AIDS Support Group of Cape Cod, Inc. v. Barnstable, 477 Mass. 296, 303, 76 N.E.3d 969 (2017), quoting Commonwealth v. Porges, 460 Mass. 525, 530, 952 N.E.2d 917 (2011). See Plumb v. Casey, 469 Mass. 593, 598, 15 N.E.3d 700 (2014), quoting Ropes & Gray LLP v. Jalbert, 454 Mass. 407, 412-413, 910 N.E.2d 330 (2009) ("When amending a statute or enacting a new one, the Legislature is presumed to be aware of prior statutory language").
Thus, we conclude that a waiver of the right to be tried by a full complement of jurors need not be in writing, notwithstanding **256rule 19 (b), where the rule no longer reflects the statutory language.3 See Commonwealth v. Pamplona, 58 Mass. App. Ct. 239, 242-243, 789 N.E.2d 160 (2003) ("truncated" colloquy without written waiver sufficient for defendant to knowingly and voluntarily waive right to counsel at criminal trial).
Importantly, although we conclude that a written waiver of this right is not required, the waiver nonetheless must be knowing and voluntary. See, e.g., Ciummei v. Commonwealth, 378 Mass. 504, 507, 392 N.E.2d 1186 (1979) ("a conviction cannot stand which follows upon a jury waiver that is not freely and knowingly given"). Accordingly, the trial judge must engage in a colloquy with the defendant to ensure that the waiver is, in fact, knowing and voluntary. The Ciummei case set forth the principles that a colloquy concerning waiver of a jury trial should cover.4 Id. at 509-510, 392 N.E.2d 1186. The same principle applies to cases where, as here, the defendant was waiving the right to a trial by the full complement of a jury.5
*1251**257A colloquy, which allows the judge to personally evaluate the defendant's state of mind and explain the nature of the jury trial right and the waiver, is in many ways more important than a written waiver -- that is, although a colloquy can be sufficient without a written waiver, a written waiver can never be sufficient without a colloquy. Cf. Commonwealth v. Pavao, 423 Mass. 798, 802, 672 N.E.2d 531 (1996) (colloquy requirement in Ciummei case is "bright line rule"). To the extent that there are concerns about documenting the waiver, we conclude that a colloquy on the record will be sufficient.
2. Validity of defendant's waiver. Here, when the juror was excused, it was defense counsel who indicated the desire to continue the trial with the five remaining jurors. A thorough colloquy was conducted on the record, in which the judge inquired as to the defendant's education and medical history, the extent of the consultation with his attorney, and his understanding of the "absolute" and "constitutional" right being waived. See note 1, supra. There is no claim that the defendant did not understand the difference between being tried by five rather than six jurors, or that he did not have an adequate opportunity to consult with counsel. After the colloquy, the judge found that the defendant's decision to go forward was made knowingly and voluntarily "beyond a reasonable doubt." The defendant does not dispute this finding.6
Conclusion. For the foregoing reasons, we conclude that the defendant's waiver of his right to a six-person jury was valid. The **258denial of his motion for a new trial is therefore affirmed.7
So ordered.