Action 4 News learned that a Weslaco capital murder suspect may have started a fatal fire as retaliation for his girlfriend breaking up with him.
Weslaco police arrested 29-year-old Mario Salinas on capital murder and attempted capital murder charges on Tuesday morning.
Salinas is accused of starting a fire October 10th at a home on the 1200 block of Valley View Road.
Investigators said 46-ear-old Melba Martinez and her 12-year-old son were killed in the blaze while a 7-year-old boy survived the fire.
Autopsy results revealed that Martinez and her son died from carbon monoxide poisoning.
Court documents filed against Salinas show that he was angry that Martinez's daughter broke up with him.
A probable cause affidavit shows that he saw her out at the Paradise nightclub on the night of the fire.
Investigators thought initially thought it was an accidental fire but later found evidence the fire was intentionally set.
An arson investigation revealed that the fire started in their home's den.
The probable cause affidavit states that neighbors saw Salinas' car leaving the crime scene.
The affidavit states that Salinas never denied starting the fire and answered "I understand" to everything.
Salinas appeared before a Weslaco Municipal Judge around 12:30 p.m. Tuesday where he received $2.5 million dollars in bonds.
Action 4 News will ahve more details on this story on Action 4 News at 5 & 6 p.m. newscasts.