A Fort Worth mother brought her 8-year-old son, teenage daughter and three other teens along with her to set nine vehicles ablaze last weekend, according to an affidavit released Friday.
Nine cars were burned in Fort Worth's historic Ryan Place neighborhood at about 4 a.m. on April 5.
The Fort Worth Fire Department announced Friday afternoon that three men and two women were arrested for the fires.
Sonja Hernandez, 39, and her daughter, Amber Hernandez, 17, were arrested. The teen's boyfriend, Jose Zapata, 19, and his twin brother, Carlos Zapata, 19, and friend Daniel Perez, 18, were also arrested.
Investigators were able to arrest all five thanks to a tip that came in after surveillance video of the suspect's vehicle was released.
A person in the neighborhood approached NBC 5 crews as they were reporting on the story earlier in the week. The information was then passed along to law enforcement officials who said it was key in making the arrests.
Investigators said Perez could be seen in the pick up truck on surveillance video.
"As far as motive goes, it's not going to be totally flushed out yet," said Brad Sims, an arson investigator for the Fort Worth Fire Department. "And we are going to hopefully come to a better understanding of that through our continued investigation."
Sonja Hernandez had her 8-year-old son with her while the fires were being set. The boy is now in the custody of Child Protective Services.
"I truly apologize to them [the victims] from the bottom of my heart," said Yaquelyn Magana, who admits she was there the night the cars were set on fire, but insists she was just a witness. "I really do. I'm apologizing for all of them."
Magana wasn't arrested and blames Sonja Hernandez, the oldest of those arrested, for starting the fire spree.
"I told them this is messed up," Magana said. "These people don't deserve this. You don't even know these people."
Magana claims she had no way to stop them. Her husband, Carlos Zapata, was one of the five arrested. However, she said her husband was not involved.
"He technically didn't participate because he didn't do anything," Magana said. "People just have the information wrong."
A sister of Carlos and Jose Zapata said even though one brother was not involved in the fires, the other did participate in the arson.
"And he was like, 'Alright, I'm going to stand up for what I did." And I give him props for that, you know," Lizbeth Zapata said. "He was like, 'What about my kids?' And I'm like, 'Well, you should have thought about that.'"
All five are currently in jail.
"It is absolutely unusual," Sims said. " We don't see this very often. It's something the city takes extremely seriously."
Investigators said they have not ruled out any kind of gang initiation.
NBC 5's Dulce Hernandez and Christina Miralla contributed to this story.