Appeal from the Superior Court of the District of Columbia (CF2-17296-07) (Hon. Brian Holeman, Trial Judge).
 The opinion of the court was delivered by: Fisher, Associate Judge
 Submitted October 21, 2010
 Before KRAMER, FISHER, and THOMPSON, Associate Judges.
 Appellant Dione Washington argues that the trial court erred when it revoked his probation upon learning that he had been convicted for criminal conduct that occurred before his probation began. Because the court knew those charges were pending at the time it imposed probation, we agree with appellant's argument and reverse.
 Appellant was arrested for acts occurring on July 24, 2007, and pled guilty on December 10, 2007, to the misdemeanor offenses of carrying a pistol without a license, possession of an unregistered firearm, and unlawful possession of ammunition.At that time, the prosecutor informed the trial court that appellant was under investigation by a grand jury for "Murder II while armed" based on conduct that occurred on June 2, 2007, and the court decided to defer sentencing to "trail the other case." However, after continuing the matter until March 19, 2008, and learning that the investigation was still pending, the trial court decided to proceed with sentencing. Appellant received three consecutive terms of one year of incarceration. All of that sentence was suspended, except for time served and two additional months' imprisonment, and the trial court imposed one year of supervised probation. The trial court did not in any way suggest that appellant's probationary sentence was conditioned on the outcome of the pending investigation.
 Appellant was later found guilty of crimes arising from his conduct on June 2, 2007, including carrying a pistol without a license, possession of an unregistered firearm, unlawful possession of ammunition, assault with a dangerous weapon, and two counts of possession of a firearm during a crime of violence; he was sentenced for those offenses on October 17, 2008. A probation officer then reported these new convictions, suggesting that appellant had violated a condition of his probation by "fail[ing] to obey all laws." On October 29, 2008, the trial court revoked appellant's probation and sentenced him to three consecutive terms of twelve months' incarceration, stating that:
 The issue here is that there is a conviction and sentencing on events that took place prior to Mr. Washington having been placed on probation . . . . The court could not have known that [the pending] matter would resolve in the way that it did and so, essentially what the court did was to give [the defendant] the benefit of the doubt . . . . The court does find that revocation is appropriate here. Had the [other] matter . . . been resolved prior to the arrest and sentencing in the instant case [the defendant] would simply not have even been considered as a candidate for probation . . . . It should be noted that the judgment in the [other matter] was entered following Mr. Washington's placement on probation . . . and it is the judgment in that case that the court finds violative of Mr. Washington's probation.
 "[T]he two primary goals of probation" are rehabilitation of the convict and protection of society from future criminal violations. United States v. Knights, 534 U.S. 112, 119 (2001). To serve these goals, probation officers are required to make reports "to the end that the court may be at all times fully informed of the circumstances and conduct of probationers." D.C. Code § 24-303 (2001).
 Recognizing the purposes of probation, we have noted that "[a] probation revocation proceeding is not a criminal prosecution; rather, it is more in the nature of an administrative hearing intimately concerned with the probationer's rehabilitation." Short v. United States, 366 A.2d 781, 785 (D.C. 1976) (citations omitted). "The decision whether to grant or revoke probation is a matter committed to the sound discretion of the sentencing court." Smith v. United States, 474 A.2d 1271, 1274 (D.C. 1983) (citations omitted). In making that determination, the sentencing court "must balance the competing interests of the community in safety with the rehabilitative goals of probation." Id. (citation and internal quotation marks omitted). However, "[t]he threshold determination whether a probationer violated a condition of probation . . . is not discretionary; it is instead a mixed question of fact (primarily, what actions did the probationer take?) and of law (did these actions constitute a violation of the probationary conditions?)." Resper v. United States, 527 A.2d 1257, 1260 (D.C. 1987) (footnote omitted).
 D.C. Code § 24-304 (a) (2001) provides, in relevant part:
 At any time during the probationary term the court may modify the terms and conditions of the order of probation, or may terminate such probation, when in the opinion of the court the ends of justice shall require, and when the probation is so terminated . . . the court may revoke the order of probation and cause the rearrest of the probationer and impose a sentence . . . .
 Although the government correctly notes that § 24-304 (a) is "a broad grant of authority" to the trial court to terminate and revoke probation, Brown v. United States, 900 A.2d 184, 188 (D.C. 2006), that authority has limits. This court has recognized that a probationer's Fifth Amendment right to due process requires that revocation be based on a showing that the probationer has "'acted in violation of one or more conditions' of his probation." Carradine v. United States, 420 A.2d 1385, 1391 (D.C. 1980) (quoting Gagnon v. Scarpelli, 411 U.S. 778, 784 (1973)). "[P]robation may not be revoked in the absence of a threshold determination that there has been a 'violation' of the express conditions of probation, or of a condition so clearly implied that a probationer, in fairness, can be said to ...