delivered the opinion of the court:
After admitting that he strangled his aunt, defendant, Carlos Izquierdo-Flores, was charged by indictment with second-degree murder (720 ILCS 5/9 — 2(a)(1), (a)(2) (West 2000)). More than 120 days after defendant filed a speedy-trial demand on the original second-degree-murder charges, the State filed a second indictment charging first-degree murder (720 ILCS 5/9 — 1(a)(1), (a)(2) (West 2000)). Relying on speedy-trial and compulsory-joinder principles, defendant moved to dismiss the second indictment, and the trial court granted his motion based upon the speedy-trial claim. The State appealed, and this court reversed and remanded the cause to the trial court on the first-degree-murder charges. People v. Izquierdo-Flores, 332 Ill. App. 3d 632 (2002). Following a bench trial, defendant was found guilty of first-degree murder and sentenced to 30 years’ *379imprisonment. Defendant appeals, arguing that: (1) we should reconsider our decision in the prior appeal in light of our supreme court’s decision in People v. Williams, 204 Ill. 2d 191 (2003); (2) the trial court erred by failing to accept his guilty plea to second-degree murder; (3) he received ineffective assistance of counsel; and (4) he is entitled to an additional day of credit against his sentence. We vacate defendant’s conviction in light of Williams and remand for further proceedings. Because of the vacatur on the first issue, we determine that the last three issues on appeal are moot, and we do not address them.
BACKGROUND
We begin by summarizing the facts preceding the first appeal in this case. On September 6, 2000, defendant was arrested in connection with the death of his aunt, Adelina Flores. According to defendant, his aunt had attacked him with a belt. Acting in self-defense, he strangled her using his bare hands. On September 7, 2000, the State charged defendant by complaint with second-degree murder. On the same date, defendant filed a speedy-trial demand. Also on that date, forensic pathologist Dr. Nancy Jones performed an autopsy on Flores’s body. The autopsy report, dated September 16, indicated that strangulation was the cause of death.
On September 20, 2000, the State filed a two-count indictment charging defendant with second-degree murder. Count I alleged that, on September 6, 2000, while committing first-degree murder and acting under a sudden and intense passion resulting from serious provocation by the victim, defendant choked Flores with his hands, thereby causing her death. Count II alleged that defendant acted under an unreasonable belief that circumstances that would justify or exonerate the killing were present.
Over the next several months, the parties agreed to several continuances and engaged in plea negotiations. During a January 16, 2001, hearing, the State sought leave to dismiss the second-degree-murder charges and file first-degree-murder charges. The State explained that the second-degree-murder charges were based on defendant’s statement to the police that he and Flores got into a fight and that, while defending himself, he strangled Flores with his hands. However, Dr. Jones’s findings showed that defendant’s theory was implausible. According to the State, Dr. Jones had been out of the country for the entire month of December. When she returned in January 2001, she reviewed the autopsy photographs and her report and opined on January 12, 2001, that the strangulation could not have been accomplished manually. Instead, she opined that the marks on *380the victim’s neck were made by a ligature, such as a rope, belt, or piece of clothing. As a result, the State now intended to pursue first-degree-murder charges. Defense counsel objected to the new charges, noting that defendant had been in custody for months and was prepared to offer a “straight” plea to the second-degree-murder charges. The trial court expressed concern over speedy-trial issues and reserved ruling on the State’s motion. The case was continued.
On January 17, 2001, the State filed a second, three-count indictment charging first-degree murder. The second indictment alleged that defendant used an object to strangle the victim. Defendant moved to dismiss the second indictment. Relying on speedy-trial principles, the trial court granted this motion. In particular, the court found that the new charges arose from the same acts that gave rise to the original charges and that the new charges were not the result of newly discovered evidence. As a result, the first-degree-murder charges were subject to the original speedy-trial term. Because the first-degree-murder charges were not before the court when defendant requested or agreed to the continuances, any delay that was attributed to defendant in connection with the original charges could not be applied to the new charges.
The trial court denied the State’s motion to reconsider and denied defendant’s request to be released pursuant to Supreme Court Rule 604(a)(3) (188 Ill. 2d R. 604(a)(3)). On February 8, 2001, the State filed a certificate of impairment and a timely notice of appeal. On appeal, the State argued that the first-degree-murder charges were not “new and additional charges.” Because the second-degree-murder charges included all of the elements of first-degree murder, the State reasoned that the first-degree-murder charges were actually before the trial court from the beginning of the prosecution. Izquierdo-Flores, 332 Ill. App. 3d at 637. In response, defendant argued that, although the second indictment did not add any new elements to the charged offense, it did place a burden on him that did not exist before. Izquierdo-Flores, 332 Ill. App. 3d at 637. Defendant pointed out that by charging him with second-degree murder, the State alleged that it could prove the elements of first-degree murder, but conceded the presence of mitigating factors. Izquierdo-Flores, 332 Ill. App. 3d at 637. Thus, if the State were allowed to withdraw the second-degree-murder charges and charge him with first-degree murder, he would be required to litigate whether a mitigating-factor was present. Izquierdo-Flores, 332 Ill. App. 3d at 637. This court agreed with the State that the first-degree-murder charges in the second indictment were not “new and additional charges.” Izquierdo-Flores, 332 Ill. App. 3d at 639. We stated that, “[bjecause the first-degree murder charges here *381do not require defendant to defend against any elements that were not before the trial court previously, allowing the State to proceed on the second indictment would not frustrate the purpose of the speedy-trial statute.” Izquierdo-Flores, 332 Ill. App. 3d at 639. Accordingly, the delays attributed to defendant in connection with the second-degree-murder charges applied to the first-degree-murder charges as well. Because the speedy-trial term had not expired when the State filed the second indictment, we held that the trial court erred by dismissing the second indictment. Izquierdo-Flores, 332 Ill. App. 3d at 639.
On remand, defendant was arraigned on three counts of first-degree murder. Pursuant to the State’s motion, the trial court dismissed the second-degree-murder charges. A bench trial commenced in January 2004, and defendant was found guilty of two counts of first-degree murder. Defendant filed a posttrial motion, which the trial court denied. The court sentenced defendant on only one count of first-degree murder, imposing a term of 30 years’ imprisonment. Defendant moved to reconsider his sentence, and the trial court denied that motion. Defendant’s timely notice of appeal followed.
ANALYSIS
Defendant first argues that we should reconsider our decision in the prior appeal in light of Williams, a case decided by our supreme court after defendant’s first appeal. Relying on Williams, defendant argues that the State violated (1) the speedy-trial statute by charging him with first-degree murder more than 120 days after he filed a speedy-trial demand on the original charges, and (2) the compulsoryjoinder statute by failing to prosecute both the first-degree-murder and the second-degree-murder charges at the commencement of the prosecution. The State responds that the law of the case doctrine bars review of this issue. While the State acknowledges that the law of the case doctrine does not limit this court’s power to revisit an issue if our initial decision was clearly erroneous and would work a manifest injustice (Bond Drug Co. v. Amoco Oil Co., 323 Ill. App. 3d 190, 198 (2001)), the State contends that Williams does not conflict with our previous decision. We disagree.
In Williams, our supreme court discussed the relationship between the speedy-trial statute and the compulsory-joinder statute. There, the defendant was originally charged with one count of contributing to the criminal delinquency of a juvenile in connection with the murder of James Patterson. Williams, 204 Ill. 2d at 196. Then, 168 days after he was arrested on the contributing charge, the defendant was also charged with one count of first-degree murder in connection with Patterson’s death. Williams, 204 Ill. 2d at 196. The defendant *382contended that the State violated the speedy-trial act when it charged him with first-degree murder 168 days after it charged him with contributing to the delinquency of a juvenile. Williams, 204 Ill. 2d at 197. According to the defendant, because these charges were subject to compulsory joinder, pretrial continuances attributable to him on the contributing charge were not attributable to him on the murder charge. Williams, 204 Ill. 2d at 197-98.
The court noted that application of the speedy-trial act is a straightforward counting exercise when a defendant is charged with a single offense; however, its application becomes more complicated when a defendant is charged with multiple, but factually related, offenses at different times. Williams, 204 Ill. 2d at 198. Under the speedy-trial statute, section 103 — 5(a) of the Code of Criminal Procedure of 1963 (Code), a defendant who is in custody shall be tried within 120 days from the date he is taken into custody. 725 ILCS 5/103 — 5(a) (West 2000). Section 103 — 5(f) provides further that the 120-day period will be suspended during any delay occasioned by the defendant. 725 ILCS 5/103 — 5(f) (West 2000).
The rule for determining the number of speedy-trial days attributable to the State when new and additional charges are brought against a previously charged defendant was first stated in People v. Williams, 94 Ill. App. 3d 241 (1981) (Williams I). Specifically, the court stated:
“Where new and additional charges arise from the same facts as did the original charges and the State had knowledge of these facts at the commencement of the prosecution, the time within which trial is to begin on the new and additional charges is subject to the same statutory limitation that is applied to the original charges. Continuances obtained in connection with the trial of the original charges cannot be attributed to defendants with respect to the new and additional charges because these new and additional charges were not before the court when those continuances were obtained.” Williams I, 94 Ill. App. 3d at 248-49.
In Williams, our supreme court reiterated its approval of this rule but stated that it applies only to new and additional charges that are subject to compulsory joinder under section 3 — 3 of the Criminal Code of 1961 (Criminal Code) (720 ILCS 5/3 — 3 (West 2000)). Williams, 204 Ill. 2d at 203-04; People v. Boyd, 363 Ill. App. 3d 1027, 1035 (2006). The compulsory-joinder provision of the Criminal Code states as follows:
“(a) When the same conduct of a defendant may establish the commission of more than one offense, the defendant may be prosecuted for each such offense.
*383(b) If the several offenses are known to the proper prosecuting officer at the time of commencing the prosecution and are within the jurisdiction of a single court, they must he prosecuted in a single prosecution, except as provided in Subsection (c), if they are based on the same act.
(c) When 2 or more offenses are charged as required by Subsection (b), the court in the interest of justice may order that one or more of such charges shall be tried separately.” (Emphasis added.) 720 ILCS 5/3 — 3 (West 2000).
Compulsory joinder requires the State to bring multiple charges in a single prosecution. People v. Quigley, 183 Ill. 2d 1, 13 (1998). The Williams court explained that the “same act” language in section 3 — 3 of the compulsory-joinder statute does not include independent acts constituting different offenses, and there is no requirement of joinder where multiple offenses arise from a series of related acts. Williams, 204 Ill. 2d at 199. Given the interaction between compulsory-joinder principles and the speedy-trial guarantee, our supreme court concluded that the speedy-trial statute should not be interpreted to require joinder that is not already mandated by section 3 — 3 of the Criminal Code. Williams, 204 Ill. 2d at 203-04.
In this case, the speedy-trial period for the original second-degree-murder charges will also apply to the first-degree-murder charges only if the first-degree-murder charges are “new and additional charges” that are subject to compulsory joinder. As previously discussed, this court held in defendant’s first appeal that the first-degree-murder charges were not new and additional charges, because the elements of first-degree murder and second-degree murder are identical. IzquierdoFlores, 332 Ill. App. 3d at 638. Our decision in that case did not address the compulsory-joinder statute, but focused only on whether the first-degree-murder counts constituted “new and additional charges.” As in the previous appeal, the State again argues that the first-degree-murder counts were not “new and additional charges,” and that Williams therefore does not control the outcome of this case. Specifically, the State argues that the new first-degree-murder charges did not contain substantial changes that altered the nature or the elements of the second-degree-murder charges. We disagree.
Second-degree murder differs from first-degree murder because of the presence of a statutory mitigating factor such as a serious provocation or an unreasonable belief in justification. People v. Porter, 168 Ill. 2d 201, 213 (1995). Thus, although the second indictment did not add any new elements to the charged offense, it did place on defendant a burden that did not exist before. A defendant charged with second-degree murder is not required to prove anything. People v. Golden, 244 *384Ill. App. 3d 908, 918 (1993). The State must prove all of the elements of first-degree murder and concede the presence of a mitigating factor. Golden, 244 Ill. App. 3d at 919. However, when a defendant is on trial for first-degree murder, to be found guilty of second-degree murder, the defendant must prove by a preponderance of the evidence the presence of a statutory mitigating factor. 720 ILCS 5/9 — 2(c) (West 2000). Thus, if the State were able to withdraw the second-degree-murder charges and charge him with first-degree murder, defendant would bear the burden of proving the presence of a mitigating factor, which places an additional issue before the trier of fact. First-degree' murder is a more serious offense with greater penalties than second-degree murder. People v. Jeffries, 164 Ill. 2d 104, 121-22 (1995). Given the distinction between first-degree and second-degree murder, we cannot assume that defendant would have agreed to continuances if he had faced both charges. We also observe that any fact that increases the penalty for a crime beyond the prescribed statutory maximum must be submitted to a jury and proved beyond a reasonable doubt pursuant to Apprendi v. New Jersey, 530 U.S. 466, 147 L. Ed. 2d 435, 120 S. Ct. 2348 (2000). There is a substantial difference in the punishments of first- and second-degree murder. Thus, the issue of a mitigating factor is an additional element or fact that distinguishes the two crimes. It is a distinction with a difference, contrary to the holding of this court in the prior appeal.
We believe that our conclusion is consistent with the rationale for compulsory joinder stated in Williams:
“If the initial and subsequent charges filed against the defendant are subject to compulsory joinder, delays attributable to the defendant on the initial charges are not attributable to the defendant on the subsequent charges. The harm in a contrary result is obvious: a trial by ambush. The State could lull the defendant into acquiescing to pretrial delays on pending charges, while it prepared for a trial on more serious, not-yet-pending charges. We cannot presume that a defendant would have agreed to a continuance if he had faced both charges. As Justice Kuehn presciently observed, ‘All choices about requests that would delay proceedings would be made under a false understanding as a result of this deception.’ When the State filed the more serious charges, the defendant would face a Hobson’s choice between a trial without adequate preparation and further pretrial detention to prepare for trial. Today, we do not create a loophole for criminal defendants. Instead, we close a loophole which would allow the State to circumvent a statutorily implemented constitutional right.” Williams, 204 Ill. 2d at 207.
Moreover, the two cases relied upon by the State that discuss *385“new and additional charges” are not relevant to this case. People v. Woodrum, 354 Ill. App. 3d 629 (2004), for example, concerned a defective indictment. See Woodrum, 354 Ill. App. 3d at 640-41 (the original indictment failed to allege a necessary element of the crime, and the defendant had been in custody for over 120 days by the time the indictment was corrected). People v. Doss, 347 Ill. App. 3d 418 (2004), on the other hand, concerned a formal rather than a substantive amendment to an indictment so that speedy-trial provisions were not implicated. See Doss, 347 Ill. App. 3d at 425-26 (the amendment of the indictment from “toy pistol” to “pistol” was formal and not substantive, because it did not alter the nature of the offense).
The State also contends that Williams is distinguishable. According to the State, this case involves essentially the same crimes, first-degree murder and second-degree murder, while Williams involved multiple but factually related crimes that occurred at different times. We disagree. Like the case at bar, the contributing and murder charges in Williams were subject to compulsory joinder because they were alternative theories on the same facts. Williams, 204 Ill. 2d at 201. As the prosecutor in Williams commented, “ ‘There is no change in discovery. There is no change in witnesses. There is no change in any evidence that would be presented. It’s preliminarily an alternative theory which may — which a jury could find based upon the same facts which were presented.’ ” Williams, 204 Ill. 2d at 201. As a result, the delays attributable to the defendant on the contributing charge were not attributable to the defendant on the murder charge, and the State violated the speedy-trial act on the murder charge. Williams, 204 Ill. 2d at 207-08. In so holding, our supreme court relied upon its earlier decision in Quigley, where the dispute centered upon whether felony driving under the influence (DUI) and misdemeanor DUI charges were based on the “same act,” and thus subject to compulsory joinder. Williams, 204 Ill. 2d at 199-200; Quigley, 183 Ill. 2d at 7. Because the felony and misdemeanor charges were based on the same act, they were required to be tried together, meaning that once the speedy-trial period expired on the misdemeanor charge, it also ran on the felony charge. Williams, 204 Ill. 2d at 200; Quigley, 183 Ill. 2d at 10, 16.
Likewise, we find People v. Derr, 346 Ill. App. 3d 823 (2004), to be instructive on the issue of compulsory joinder. There, the defendant was initially charged with involuntary manslaughter and concealment of a homicidal death. Derr, 346 Ill. App. 3d at 826. Almost three years after the original charges had been lodged and almost three years after the defendant had demanded a speedy trial on those charges, the State filed a motion for leave to file an amended information that charged first-degree murder. Derr, 346 Ill. App. 3d at 826. According *386to the State, no prejudice would result to the defendant from the desired amendments, because the additional counts did not arise out of any additional facts or circumstances. Derr, 346 Ill. App. 3d at 826. The court disagreed, stating that, “[i]n effect, the motion set forth why the new charge was subject to compulsory joinder.” Derr, 346 Ill. App. 3d at 826. The court went on to say that defense counsel’s failure to pursue the defendant’s speedy-trial rights denied the defendant a legal avenue that would have protected him from the murder charges. Derr, 346 Ill. App. 3d at 827. In other words, the new charges should have been joined in the charging instrument from the prosecution’s inception, and none of the numerous continuances obtained on the original charges had tolled the speedy-trial demand on the new charges. Derr, 346 Ill. App. 3d at 827.
As we stated in our previous decision, there is no question that the second indictment arises out of the same incident upon which the original charges were based. Izquierdo-Flores, 332 Ill. App. 3d at 639. In addition, this is not a case where the delay in filing the first-degree-murder charges was due to the discovery of new evidence. Instead, as we previously found, the delay was the result of the State’s lack of diligence in investigating the case. Izquierdo-Flores, 332 Ill. App. 3d at 639-40. In light of our supreme court’s discussion of the relationship between the speedy-trial statute and the compulsory-joinder statute in Williams, we must reconsider our previous decision and now reach an opposite result. Because the original second-degree-murder charges and the new first-degree-murder charges were based on the same act of strangling Flores, the charges were subject to compulsory joinder. Under Williams, if initial and subsequent charges filed against a defendant are subject to compulsory joinder, delays attributable to the defendant on the initial charges are not attributable to the defendant on the subsequent charges. Williams, 204 Ill. 2d at 207. As a result, the delays attributable to defendant on the second-degree-murder charges were not attributable to defendant on the first-degree-murder charges, and the State violated the speedy-trial act with respect to the first-degree-murder charges. Accordingly, defendant’s conviction is vacated. See Williams, 204 Ill. 2d at 207-08.
We believe, in light of the Williams decision, that our initial decision was clearly erroneous and would work a manifest injustice (see Bond Drug Co., 323 Ill. App. 3d at 198) were we not to vacate the proceedings on remand and reinstate the status quo ante. See Applegate v. Department of Transportation, 335 Ill. App. 3d 1056, 1063 (2002) (vacatur restores the status quo ante, as though a judgment had never been entered). As this court explained in People v. Eidel, 319 Ill. App. 3d 496, 504 (2001): “To ‘vacate’ a judgment is to nullify *387or cancel it. [Citation.] A judgment that has been vacated is void. [Citations.] It is ‘entirely destroyed.’ [Citation.] The vacatur restores the parties to the status quo ante, as though the trial court judgment had never been entered.” Eidel, 319 Ill. App. 3d at 504; see also Williamsburg Village Owners’ Ass’n v. Lauder Associates, 200 Ill. App. 3d 474, 483 (1990) (ascribing similar effect to reversal). Had the trial court’s judgment in the prior appeal been affirmed, the case would have proceeded to trial on only the second-degree-murder charges. It is noteworthy that defendant claims that the trial court abused its discretion when it failed to accept his blind plea of guilty to the charge of second-degree murder, and he requests that we “remand the case to the trial court with instructions that the trial court allow the defendant to plead anew to second degree murder.” We believe that such an admonishment is unnecessary because the disposition entered in this cause is for further proceedings relating only to the second-degree-murder charges.
CONCLUSION
For the above reasons, defendant’s conviction of first-degree murder is vacated and the cause is remanded for further proceedings consistent with this opinion.
Vacated and remanded with directions.
BYRNE, J., concurs.