Short answer. Because the Rules allow it for sentencing. Under Rule 116, when the accused pleads guilty to a non-capital offense, the court may receive evidence from the parties to determine the penalty to be imposed. The plea settles guilt; the evidence helps the judge fix the right punishment within the law's range.
What the law says
When the accused pleads guilty to a non-capital offense, the court may receive evidence from the parties to determine the penalty to be imposed.
Rule 116, Section 4 — Plea of guilty to non-capital offense; reception of evidence, discretionary. Read the full provision →
What the rule says, and what it is for
Rule 116, Section 4 is one sentence: When the accused pleads guilty to a non-capital offense, the court may receive evidence from the parties to determine the penalty to be imposed. The hearing you are watching is not a trial of your guilt — the plea disposed of that. Penalties in Philippine law are almost never single fixed numbers; they come in ranges and degrees, moved up or down by the circumstances of the offense and the offender. The evidence being received exists to place your case correctly within that range, and nothing in the rule reopens the question the plea already answered.
Both sides get to be heard
The rule says evidence from the parties — it is not a stage reserved for the prosecution. The prosecution may present matters bearing on how the offense was committed; the defense may present the circumstances that tell in your favour — the context of the act, restitution made, and the personal circumstances the court may weigh. For an accused, this is the practical takeaway: the sentencing hearing is an opportunity, not a formality. Evidence that humanises the case and supports the mitigating side of the ledger belongs here, and counsel should treat the hearing as worth preparing for.
Discretionary here, stricter for capital offenses
Notice the verb: the court may receive evidence. For non-capital offenses the reception of evidence is discretionary — where the penalty is straightforward and the facts undisputed, a court can proceed to sentence on the plea alone; where the range is wide, hearing evidence is the careful course. The Rules treat a plea of guilty to a capital offense very differently: there the safeguards are mandatory, with the court required to probe the voluntariness of the plea and the prosecution required to prove the case notwithstanding it. The relaxed, optional character of the hearing you are in is itself a marker that your case is in the non-capital lane.
What this means for you
Do not read the continued reception of evidence as a sign your plea was rejected or that a conviction is being rebuilt from scratch. It means the judge wants a fuller picture before fixing the penalty — which can work in your favour if the fuller picture is prepared. Talk to your counsel about what the defense will offer at the hearing, gather the documents that support mitigation, and understand from counsel what range the law attaches to the offense you admitted, so the sentence, when it comes, arrives explained rather than as a surprise.