MANILA -- The man suspected of killing his own wife and 18-year-old son claimed he acted in self defense when he shot them last week in their home in Maragondon, Cavite. The suspect, Danilo Rafael Sr., said he discovered exchanges of text messages between a man and his wife Fe on the latter's cellphone last Thursday, triggering an argument. He claimed his wife started shouting at him when he started asking about the text messages. He said he began to suspect that his wife was having an affair in 2012. During the confrontation, he said his son Rafael tried to stab him, forcing him to defend himself with a gun. He then shot his wife, claiming he was already out of his mind. Rafael said he went on to finish off his son by smothering him with a pillow and shooting him once more in the head. Rafael was caught on closed-circuit television (CCTV) camera abandoning a Ford Fiesta car near his wife's relative's house along Timothy Street in Multinational Village, Parañaque City. The bodies of the victims were then discovered inside the car's trunk. The suspect was arrested by authorities in Tuguegarao City, Cagayan on Tuesday through the help of a police informant. He is facing parricide and illegal possession of firearms charges. – report from Dennis Datu, dzMM; ANC