Fugitive mother is said to have fled to India and is now wanted for the murder of her son

When police knocked on her door on March 20, 2023, asking about her six-year-old son, Cindy Rodriguez Singh allegedly told officers he was in Mexico with his father.

Two days later, Rodriguez Singh, her husband and six children boarded a plane to India, authorities said.

The missing child – Noel Alvarez – was not on board the flight. He has not been seen since and is presumed dead.

Last week, the FBI and Everman Police Department in Texas offered a $25,000 reward for “information leading to the arrest and conviction” of the boy’s 39-year-old mother, who is charged with capital crimes in connection with her son’s case.

Police Chief Craig Spencer said in a statement that the mother’s “immediate arrest” was “incredibly important,” not only “in the interest of justice” but also for “the safety of the other children in her care.”

Katie Chaumont of the FBI’s Dallas division told PEOPLE that the FBI – which is “working to locate the mother” while the investigation into Noel’s death continues locally – has received several tips since the award was first presented and will “carefully review each one for information that could lead to Rodriguez Singh’s whereabouts.”

According to both law enforcement agencies, Noel has not been seen alive since October 2022.

The child was seen twice this month: once when his mother gave birth to twins and another time when he appeared “malnourished” and “unhealthy,” PEOPLE previously reported from a law enforcement news release.

Five months later, relatives called the police, which led to a welfare check in March 2023.

Investigators claimed they later refuted Rodriguez Singh’s claim that Noel had been with his biological father in Mexico since November 2022, PEOPLE previously reported, citing police.

On another occasion, authorities said, the mother told people who asked about her son that she had sold him to a woman in a grocery store parking lot.

However, law enforcement authorities believe the child is most likely dead.

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Shortly after the birth of her twins, police alleged that Rodriguez Singh called her son – who Spencer said in an interview with PEOPLE is mentally disabled and has developmental disabilities – “evil” and “possessed.” She said there was a “demon” inside the six-year-old and believed he would harm the infants, PEOPLE previously reported.

According to authorities, a month after the twins were born, the mother applied for passports for six of the seven children in the household – all except Noel.

While investigating the child’s disappearance, law enforcement discovered that the family of nine – who lived in a red shed in Everman, Texas – had demolished a second shed on the property and poured a concrete patio where it had previously stood, according to Spencer, who called the demolition a reflection of “very suspicious circumstances.”

Carpeting found in the shed was tracked down by cadaver dogs and allegedly indicated human remains. This led to a warrant for investigators to tear up the concrete patio, according to Spencer. He said a second group of sniffer dogs alerted them that “human remains had once been in the shed.”

Before Noel’s presumed death, the family lost custody of Noel and his siblings, who were placed in foster care, according to Spencer. Noel was placed separately from his siblings in another foster home that catered to his special needs. Eventually, social workers returned the children home.

Relatives believed that Rodriguez-Singh “abused and neglected Noel,” authorities previously claimed in a news release. A relative later reported seeing the mother hit the child in the face with her keys after he took a sip of water. Several people told authorities that the water was “often withheld” from the child — as well as food — because she “didn’t like changing Noel’s dirty diapers.”

According to the police chief, the mother never enrolled her son in school.

The U.S. District Court for the Northern District of Texas issued a federal arrest warrant for Rodriguez Singh on November 2, 2023, after she was charged with unlawful flight from law enforcement.

According to authorities, Rodríguez Singh – who is just over 5 feet tall and has numerous tattoos – has ties to both India and Mexico.

Anyone with information on the whereabouts of Cindy Rodriguez Singh can call the FBI Dallas Field Office at 972-559-5000 or submit a tip online at tips.fbi.gov.

If you suspect child abuse, call the Childhelp National Child Abuse Hotline at 1-800-4-A-Child or 1-800-422-4453, or visit www.childhelp.org. All calls are toll-free and confidential. The hotline is available 24 hours a day, 7 days a week, in more than 170 languages.