CYPRESS, Texas - Newly obtained court documents explain how a pair of handcuffed, malnourished twins managed to sneak out of their home in Texas, prompting their mother to flee hundreds of miles with her remaining children back to their hometown of Baton Rouge.

While the family's house, nestled in an upscale Texas neighborhood, looked like a dream home from the outside, the children said they endured nightmarish punishment at the hands of their mother Zaikiya Duncan, 40, and her live-in boyfriend Jova Terrell, 27.

The 15-year-old twins — a boy and a girl — plotted their escape after months of abuse at the Cypress home, investigators learned. The boy, who was reportedly forced to live in a laundry room with his twin sister, said he found the key to their handcuffs inside his mother's purse and then hid the key in his mouth. Once their mother and her boyfriend fell asleep Monday night, the two unlocked their restraints and ran out of the house.

Footage captured on neighbors' surveillance cameras showed the emaciated teenagers going door-to-door, desperate for help. A good Samaritan eventually let them inside her home and called 911.

"They told me details about what they endured, what the mom has put them through," said the woman, who asked to remain anonymous. "The more I looked at them, the more I could see the abuse... Literally they were just skin and bones."

Both teens had scarring on their wrists where they tried to get free of the cuffs, and the girl was wearing a grocery bag around her neck which she used as a shirt. 

After speaking with the teens, deputies went to the family's home early Tuesday morning to find that Duncan and her boyfriend had vanished with her remaining children, five kids ages 7 to 14. Authorities issued an Amber Alert out of Harris County, and police tracked them to a parking lot on Nicholson Drive in Baton Rouge, just off LSU's campus, hours later Tuesday afternoon. 

State troopers found one of the missing children with the suspects, who told police they left the others with a family member who lived in the area. All five children were eventually found safe, according to Louisiana State Police.

Duncan and Terrell were booked into jail in East Baton Rouge and will be shipped back to Texas to face charges including aggravated assault of a family member and continuous violence against family.

Charging documents from Harris County prosecutors revealed just how far the abuse went. 

The teenagers claimed Duncan would make them drink bleach or spray cleaning chemicals into their mouths whenever they "talked too much," adding that she would pour bleach on her children's skin — including their genitals — leaving them with burns. The documents also allege the victims had no access to a bathroom and were forced to swallow their own urine and feces at some point. 

The twins said they survived by drinking water from the supply valve attached to the washing machine and that they were only given one to three sandwiches to live off of each week. 

The couple is also accused of forcing the kids to take dangerous amounts of Benadryl to make them sleep — causing one of them to have a seizure — and beating the teens, Terrell allegedly using his fists and Duncan reportedly swinging metal rods and an extension cord. 

Duncan was also previously convicted in a Baton Rouge child abuse case involving her kids after another arrest in 2012.