David A. Zane Jr. would spend the next few years living with friends or his girlfriend (they would have a daughter together, now 2), or in the streets.
So on Sept. 6, four years after she had thrown him out of her Mantua Township house - relenting only briefly late last year - MacMullin, 45, refused to be at her son's side again. This time he was facing a Superior Court judge in Gloucester County to be sentenced for burglary and theft.
In a riveting scene, an assistant prosecutor read to the court a statement e-mailed by one of David's three burglary victims - his mother.
MacMullin addressed the letter directly to her wayward son, now 25.
The day he was being sentenced, she noted, was important to the family for another reason: They were driving his 18-year-old sister, Morgan, to college in Providence, R.I.
"Instead of allowing today to be about you, David, today is about your sister," MacMullin wrote.
"You will never know the heartache that you have caused me, and I'm not so sure that you care. I have forgiven you for what you took from me, David. This was never about that. Your drug problems have turned you into a person I no longer recognize.
"I hope whatever jail time you receive, David, you take to reflect on the many things you have done wrong and getting serious help for your drug addiction."
Shackled, he said in court he wished his mother were there, according to Bryant Flowers, the prosecutor who read the e-mail.
The letter offered a poignant, public glimpse of how a son's eight-year drug habit fractured a family and alienated a mother, who resolved to focus on her other child. She hoped her firmness would force her older child to get his life together.
Her son's life seemed to unravel, MacMullin recalled last week, after he caused the death of his best friend, a fellow Clearview Regional High School student, in 2005 in a drunken-driving crash. "I know he's never forgiven himself."
She tapped out the letter on her iPhone the night before the sentencing. She found an assistant county prosecutor's e-mail address online and sent her letter about 10:30 p.m. That prosecutor, Mary Pyffer, passed it to Flowers.
This victim-impact statement - firm, but also bravely compassionate - was unusual, according to Gloucester County prosecutors.
"She gave a very powerful statement, which I believe not only voiced her personal dilemma with her son," County Prosecutor Sean F. Dalton said. "But it was also a story that I'm sure a lot of families can relate to in dealing with the struggle of addiction."
At Clearview, David was a class clown. Once he disrupted Spanish class by tapping his desk with two pencils, like a drum set.
In September 2005, then 17, he drove off the road, careered down an embankment, and crashed into a utility pole on the way home from a party at Rowan University. Michael Mariano, 16, was ejected and died at the scene.
David's blood-alcohol content was over the legal limit, MacMullin said.
He performed CPR on Mariano and stayed with him until police arrived. At the hospital, he learned his friend had died.
"I looked into his eyes and I saw this sadness. I knew . . . that he was never going to be the same," his mother said.
David, convicted of vehicular homicide, served a year between prison and a halfway house.
Then he started using marijuana. Then heroin.
In one incident, a Camden officer offered David leniency. He did not arrest him and a friend when the two tried to buy drugs.
"I gave him a choice: Either you give me your parents' number or I will throw your a- in jail," MacMullin said the officer told her on the phone.
The family tried its own discipline, confining him to the house, not allowing him to have friends visit.
In one of the overdoses, MacMullin heard a thud in the bathroom, and the wheezing that still haunts her.
MacMullin said she gave him CPR. Morgan, then 14, stood in the doorway staring at her brother. "I will never forget the look on her face," MacMullin said.
David never finished any of the rehabilitation programs to which his family sent him. Once he abruptly left a Florida rehabilitation facility and asked his mother for plane fare. She refused. A girlfriend gave him bus money.
Banishing David "was sad, but it was necessary. He was still doing drugs, and it was for the safety of Morgan" MacMullin said.
Still, the mother-son bond was not severed.
He sent her text messages nights saying he loved her, and he visited for family gatherings.
She spent uneasy nights. From her front porch, she watched for flashing lights, expecting a uniformed messenger to tell her that her son had died of an overdose.
"It has always been a struggle with me, making those really tough decisions," she said. "Being his mother, I always harbored a lot of guilt. I kind of always felt like what kind of mother am I that my son, his life, has turned out this way."
Her father, Joe McCart, a semiretired computer-parts salesman, guided by his Catholic faith, tells her to keep praying.
"I do know that we all have to find forgiveness in our hearts, because there will be a time when he is sincerely going to try to get better and we have to be there to help him," McCart said.
The family relented and let David move back into the house last November. Then in February, he cracked his mother's safe and stole her wedding ring. The diamond in the ring had been passed down from MacMullin's grandmother, who died in 1976.
"I know somewhere, deep inside, that wonderful little boy that I raised still exists," she said.
Morgan is studying to be a pastry chef at Johnson & Wales University, in Providence. She is taking English, math, biology, and public speaking this freshman semester. A former Clearview classmate, who enrolled early, showed her how to press her uniform.
Her brother is serving a year in prison.
Contact Darran Simon at 856-779-3829 or at firstname.lastname@example.org, or follow on Twitter @darransimon.