Homicide case against mom whose breastfed baby died with drugs in his system can proceed, judge rules Samantha Jones' attorney said she is living "a little piece of hell on Earth."

The homicide case against a breastfeeding mom whose baby died after drugs were found in his system can move forward, a Pennsylvania judge has ruled.

Samantha Jones, 30, has been charged with one count of criminal homicide after her 11-week-old son, R.J., died after being breastfed on April 2.

Jones had been taking methadone, a drug she had been prescribed by doctors to help fight an addiction to painkillers, according to an affidavit of probable cause filed July 13.

A combination of methadone and two illegal drugs, amphetamine and methamphetamine, were found in the baby's system, according to the affidavit, which states that "R.J. ingested the combination of fatal drugs through breast milk."

During a preliminary hearing Wednesday, Jones' attorney, Louis Busico, had tried to get the homicide charge dismissed, arguing that Jones' breast milk had not been tested for drugs and that she would never have harmed R.J.

"She was a wonderful mother to this little boy. I can tell you she was a loving mother to this little boy, and she was doing everything possible to improve herself and provide both her children and herself with a nice life," Busico told ABC News. "She has another child who she loves dearly. She has an amazingly close and wonderful relationship with her own mom. But every day is a little piece of hell on earth, make no mistake about it."

Magisterial District Judge Lisa J. Gaier of Richland Township, however, ruled Wednesday that the case against Jones can proceed. Jones will be formally arraigned on Sept. 28 in Doylestown, Pennsylvania, according to the district attorney's office.

Deputy District Attorney Kristin McElroy argued during Wednesday's hearing that R.J. had died because Jones had used methamphetamine and amphetamine, substances she said "had no business being inside that baby."

"We are not alleging that this was an intentional killing of this baby," McElroy said, according to a press release issued by the Bucks County District Attorney's Office.

McElroy added that "it certainly was reckless to know these drugs were in your body and continue to breastfeed."

Jones, who is at home awaiting arraignment, declined to comment through her attorney.

Jones had switched to feeding R.J. with formula in the days before his death because she was trying to "re-up her supply" of breastmilk, according to the affidavit.

But around 3 a.m. on the morning of April 2, "R.J. was crying and because she was too tired to go downstairs and make a bottle of formula, she tried to breastfeed him but wasn't sure if he latched onto her breast and received any milk," according to the affidavit. Jones then fell asleep for several hours, according to the affidavit.

Around 6 a.m., Jones' husband prepared a bottle of formula for R.J., which Jones fed him before putting him down in his bassinet around 6:30 a.m. and going back to sleep herself, according to the affidavit.

When Jones woke up about an hour later, she "observed R.J. to be pale, with bloody mucous coming out of his nose." She and her mother called 911 and initiated CPR, according to the affidavit.

R.J. was transported to Doylestown Hospital in an ambulance and was pronounced dead at 8:29 a.m. in the emergency room, according to the affidavit.

Authorities said no illicit drugs were found in the remaining formula in R.J.'s bottle or in the formula container, which were both tested, according to the affidavit.

During the preliminary hearing Wednesday, Busico had argued that it was unclear how the illegal drugs -- amphetamine and methamphetamine -- had entered R.J.'s system. Jones, who Busico said has one other child, had been using methadone with a prescription and told police as much, according to the affidavit.

Methadone is prescribed to help people who are battling an addiction to narcotic-based painkillers.

According to a study on breastfeeding and methadone published in Breastfeeding Med in 2008, "concentrations of methadone in human milk are small, and the potential exposure to the infant is low and unlikely to have any negative effect on the developing child."

Similarly, a 2008 report published in the official publication of the College of Family Physicians of Canada, "the exposure of infants to methadone through their mothers' breast milk is minimal" and "women using methadone for treatment of opioid dependence should not be discouraged from breastfeeding."

"I can tell you that at the time her child was born, she was lawfully taking methadone, that the hospital knew of it and she was discharged with instructions to continue using it as prescribed," Busico said.

Few studies have been conducted about the use of recreational use of methamphetamine or amphetamine and its impact on breastfeeding, but a report published in 2009 in the British Journal of Clinical Pharmacology showed that amounts of the drug did pass into breast milk and recommended women wait 48 hours after drug use to breastfeed.

The study relied on a sample of two mothers, however.

Busico has argued that it's not clear how the illicit drugs got into the baby's system.

"From some of the reports that were produced [Wednesday] at the preliminary hearing -- they unequivocally state, that's the toxicology reports and the autopsy reports -- that the source of the amphetamine remains unknown and unexplained," Busico said. "So the government isn't really in a position to explain the source."

McElroy told ABC News that because the case is ongoing, she is not able to answer questions as to whether Jones or her breast milk were tested for drugs at the time of R.J.'s death and how the drugs might have entered the baby's system.

Busico said Jones should have never have been prosecuted in the first place.

"In terms of why this case is being prosecuted, you have to ask the people who chose to do it. I will do everything in my power to have this young woman exonerated," Busico said. "But regardless of how any case plays out, there is no punishment that she could be given that's worse than the sentence she is currently serving by not having that little boy in her home."