The office said Wednesday it wouldn't be able to prove the charge of assisted suicide against Alan Purdy in the March death of his wife, Margaret, the Los Angeles Times reported.
"We do not discuss the reasons when we don't file criminal charges,'" said district attorney spokesman Steve Walker, "other than [to say that] we only file when we believe we can prove the case beyond a reasonable doubt."
Purdy said he sat beside his wife as she ate apple sauce mixed with sleeping pills and put a plastic bag over her head in their San Marcos, Calif., home.
"I didn't want her to feel abandoned. I wanted her to know that I loved her," Purdy told the Times.
Margaret Purdy, 84, had reportedly been bedridden for years with severe pancreatitis, an autoimmune disease, a crumbling spine and three fractured vertebrae that wouldn't heal.
The couple had been married for 15 years and each had children from previous marriages. Both sets of children were opposed to criminal charges, the Times reported.
"I'm delighted to hear this," said Purdy's daughter Catherine Purdy, of the district attorney's decision. "I feel like justice has finally happened. He lost his wife, and then to have to wait for this decision -- it's been very hard on him."