Update at 6:02 p.m. ET: Police are shutting down the northbound lanes of I-95 in West Palm Beach because of a potentially dangerous chemical found in the pesticide truck where a 10-year-old boy was found critically injured, the Associated Press says. Police have not identified the chemical.

The boy, Victor Barahona, told police his father, Jorge, had doused him with a chemical.

The decomposed body of his twin sister was found wrapped in plastic in the back of the pickup. It's not yet clear how or when she died.

Jorge Barahona, 53, has been charged with aggravated child abuse. He was found unconscious and seriously burned and is in intensive care at a local hospital.

Update at 3:17 p.m. ET: A West Palm Beach police report says the father confessed to putting his dead adopted daughter in a bag in his truck and driving to Palm Beach County with the intention of killing himself, The Palm Beach Post reports.

The police report says Jorge Barahona told officers he was "distraught" over her death and planned to set himself on fire, but decided not to because that might also kill his son, Victor, who is the dead girl's twin.

But the police report notes that the boy had "prior injuries" on his body, including a broken collarbone, broken arms and rope marks on both wrists, and concludes that "Jorge's account of events is inconsistent" with the injuries.

NBC Miami reports that it remains unclear how and when the daughter died.

The Miami Herald reports that the Barahona couple has twice been reported to the Department of Children and Families for possible abuse.

In the most recent incident, The Herald reports, Barahona' s young granddaughter told a therapist last week about a "family secret" regarding how the twins were treated. She said the pair were bound by hands and feet and forced to stay in the bathroom, The Herald reports.

Earlier posting: The Palm Beach Post has a bizarre story today about a 10-year-old boy found dripping in acid and writhing with seizures inside an old pickup along I-95 in Florida.

His adoptive father, Jorge Barahona, 53, was found unconscious next to him in the vehicle.

Even more shocking, authorities found a corpse wrapped in a black garbage bag among tubs of unlabeled chemicals, the newspaper says.

NBC Miami reports today that the body is that of the boy's twin sister.

Officials identified Barahona as a pest exterminator who lives in Miami-Dade County, where he and his wife are raising four adopted children, all under the age of 11, the newspaper reports.

Although Barahona remains in intensive care at a West Palm Beach hospital, police arrested him Monday night on a felony charge of aggravated child abuse involving the injured boy, his adopted son, Victor.

Victor, who was described as suffering "severe internal reactions" from inhaling chemicals, is in critical condition, the Post says.