By Matt Goodman & Arezow Doost, CBSDFW.COM

Updated 5/19, 6:31 a.m.

CONCORD, Mass. (CBSDFW.COM) – An Irving mother is in police custody in Massachusetts after telling authorities she killed her son and dumped his body on the side of the road near the border of Maine and New Hampshire over the weekend, sources told the CBS station affiliate in Boston.

Julianne McCrery, 42, was taken into protective custody Wednesday after she told arresting officers that 6-year-old Camden Pierce Hughes, her son, died after she gave him an overdose of his cough syrup medication. As of Wednesday night, she had not been charged.

Authorities found the child’s body Saturday at about 5:30 p.m. near the New Hampshire border in South Berwick, Maine, wrapped in a blanket next to a dirt road. Police suspected the body had been there since 7:30 a.m. that morning.

Witnesses told police they saw a blue Toyota Tacoma pickup truck at the scene. A Massachusetts state trooper spotted a truck that matched witnesses’ descriptions at a rest stop just off Interstate 495 Wednesday at about 10:20 a.m., about 65 miles from where the boy’s body was found.

camden pierce hughes Irving Mom Arrested In Massachusetts For Sons Death

A picture of Camden Pierce Hughes, the son of Irving resident Julianne McCrery. The body of the six-year-old was found on the side of the road in Maine. (credit: Facebook)

McCrery was driving the truck. Sources told WBZ NewsRadio 1030 in Boston that the 42-year-old identified the child as her son and that she gave him an overdose of his medication, killing him.

According to WBZ-TV, the medical examiner finished an autopsy over the weekend, but the official cause of death was determined to be asphyxiation.

“We were together for two years, but I’ve known (the boy) since the day he was born,” Robert Miller, McCrery’s ex-boyfriend who also lives in Irving, told WBZ-TV. “He was a very nice boy. He was an innocent boy.”

On Wednesday, friends gathered at the church McCrery sometimes attended to cope with the tragedy and find solace. Close friends called McCrery a good mother and a passive person who wouldn’t harm anyone – especially not her own son.

“Whatever happened, she was trying to help him and it backfired,” said close friend Hillary Watson. “She loves him! She would have never intentionally tried to hurt him.”

The truck, which WBZ-TV reported had Navy insignia on its license plate, is in the police barracks awaiting processing.

Soon after police found the boy’s body Saturday, authorities released a computer-generated photo, hoping someone would recognize him.

Police said they received about 60 tips from Maine, New Hampshire and Ohio. The photo was given to schools, day cares, pediatrician offices and the National Center for Missing & Exploited Children, WBZ-TV reported.

McCrery delivers auto parts and she also wrote a book called “Good Night, Sleep Tight,” which is meant to help those having trouble sleeping.It is not clear why McCrery was in Maine.

She was arrested in Dallas County in 2003 for prostitution and 2004 for possession of a controlled substance with intent to deliver. Both those cases were dismissed.