This is the next mission in the main storyline. Larissa tells you that she has heard of someone else who may have information about the car bomb that killed Ana. This man is named Paco, so head to his hideout to talk to him. As soon as Paco knows why you're there, he gets on his motorbike and drives off. You need to give chase - eventually, after passing through some parkland, he will get off and run on foot. This is your chance, so you should also get off your bike and beat him up until he tells you what you need to know.
He advises you to talk to Victor, the head of the Disciples. Victor tells you that Veronica Davo, the leader of the Syndicate, put the hit on Raul and Ana, but whoever killed them never collected their reward. He suggests Veronica herself, or the police may have been the assassins.
Reward: 1,000R$