The children are believed to be in Texas

3 Missing Connecticut Children Believed to Be with Convicted Sex Offender, in 'Grave' Danger

The nationwide search for three Connecticut children continues, with officials issuing an AMBER Alert over the weekend after the missing siblings were spotted in the southeastern city of Sealy, Texas.

Police in Waterbury, Connecticut, confirm Maddison McGrath, 7, Dylan McGrath, 5, and Maryah Matthew, 2, remain missing, and are believed to be with their non-custodial mother, Chrystal McGrath, who allegedly went on the run with them back on February 16, and Chrystal McGrath’s boyfriend, Lester Joy, who is a registered sex offender according to WFSB.

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Authorities say in the AMBER Alert the kids are in “grave” danger.

The 29-year-old mother recently lost custody of the three children, but was allowed supervised visits with them.

According to police, McGrath left a McDonald’s in Waterbury with her kids, allegedly violating the terms of a court-mandated arrangement. Police confirm she vanished after going into the restaurant’s bathroom with the three siblings.

Image zoom Chrystal McGrath Waterbury Police Department

Detectives are tracking down every lead they have received about the missing children.

The children’s grandmother, who asked to remain unnamed, spoke to WFSB, pleading for their safe return.

“She left the coats, the diaper bag and gone,” the grandmother said. “She took them without their coats. Bring them home. You are confusing them. They’re probably scared. Yes, you’re the mom. But they don’t know what’s happening. Bring them home.”

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Maddison is a female with brown eyes and black hair. She stands about 4 feet tall, and weighs about 40 lbs.

Dylan is a male with green eyes and brown hair. He, too, is about 4 feet tall and weighs about 50 lbs.

Maryah is a female with brown eyes and black hair. She is a foot tall and weighs about 30 lbs.

McGrath could be driving a red or maroon sedan with Connecticut plates 417-YTY. The vehicle could either be a Honda or a Volvo, according to police.

She was last seen wearing a black shirt and black pants or tights.

According to NJ.com, Joy was convicted in New Jersey in 2002 of second-degree sexual assault, third-degree endangering the welfare of a child and third-degree theft. He was sentenced to three years in prison and lifetime community supervision. Additionally, a judge ordered him to register as a sex offender.

In 2006, Joy, 38, was convicted in New York of third-degree rape, third-degree criminal sexual acts, and disseminating indecent material to a minor. Authorities said he lured a 16-year-old girl from her home, driving her to a Juarez, Mexico.

He was released from prison in 2013, and in 2015, was apprehended in Connecticut for failing to register as a sex offender.