"To summarize, Milan’s and Chua’s arguments focus on the lack of direct evidence showing that they conspired with Carandang during the latter’s act of shooting the three victims. However, as we have held in People v. Sumalpong,  conspiracy may also be proven by other means:
Conspiracy exists when two or more persons come to an agreement concerning the commission of a felony and decide to commit it. Evidence need not establish the actual agreement among the conspirators showing a preconceived plan or motive for the commission of the crime. Proof of concerted action before, during and after the crime, which demonstrates their unity of design and objective, is sufficient. When conspiracy is established, the act of one is the act of all regardless of the degree of participation of each.
In the case at bar, the conclusion that Milan and Chua conspired with Carandang was established by their acts (1) before Carandang shot the victims (Milan’s closing the door when the police officers introduced themselves, allowing Carandang to wait in ambush), and (2) after the shooting (Chua’s directive to Milan to attack SPO1 Montecalvo and Milan’s following such instruction). Contrary to the suppositions of appellants, these facts are not meant to prove that Chua is a principal by inducement, or that Milan’s act of attacking SPO1 Montecalvo was what made him a principal by direct participation. Instead, these facts are convincing circumstantial evidence of the unity of purpose in the minds of the three. As co-conspirators, all three are considered principals by direct participation.
Appellants’ attempt to instill doubts in our minds that Chua shouted “sugurin mo na” to Milan, who then ran towards SPO1 Montecalvo, must fail. SPO1 Estores’s positive testimony on this matter prevails over the plain denials of Milan and Chua. SPO1 Estores has no reason to lie about the events he witnessed on April 5, 2001. As part of the team that was attacked on that day, it could even be expected that he is interested in having only the real perpetrators punished.
Furthermore, we have time and again ruled that factual findings of the trial court, especially those affirmed by the Court of Appeals, are conclusive on this Court when supported by the evidence on record. It was the trial court that was able to observe the demeanors of the witnesses, and is consequently in a better position to determine which of the witnesses are telling the truth. Thus, this Court, as a general rule, would not review the factual findings of the courts a quo, except in certain instances such as when: (1) the conclusion is grounded on speculations, surmises or conjectures; (2) the inference is manifestly mistaken, absurd or impossible; (3) there is grave abuse of discretion; (4) the judgment is based on a misapprehension of facts; (5) the findings of fact are conflicting; (6) there is no citation of specific evidence on which the factual findings are based; (7) the finding of absence of facts is contradicted by the presence of evidence on record; (8) the findings of the Court of Appeals are contrary to the findings of the trial court; (9) the Court of Appeals manifestly overlooked certain relevant and undisputed facts that, if properly considered, would justify a different conclusion; (10) the findings of the Court of Appeals are beyond the issues of the case; and (11) such findings are contrary to the admissions of both parties.
Neither can the rapid turn of events be considered to negate a finding of conspiracy. Unlike evident premeditation, there is no requirement for conspiracy to exist that there be a sufficient period of time to elapse to afford full opportunity for meditation and reflection. Instead, conspiracy arises on the very moment the plotters agree, expressly or impliedly, to commit the subject felony.
As held by the trial court and the Court of Appeals, Milan’s act of closing the door facilitated the commission of the crime, allowing Carandang to wait in ambush. The sudden gunshots when the police officers pushed the door open illustrate the intention of appellants and Carandang to prevent any chance for the police officers to defend themselves. Treachery is thus present in the case at bar, as what is decisive for this qualifying circumstance is that the execution of the attack made it impossible for the victims to defend themselves or to retaliate."