Benton Mackenzie answers questions along side his wife Loretta and their son Cody, 22, after the three were sentenced to probation Tuesday Sept. 9, 2014 at the Scott County Courthouse in Davenport, Iowa.

DAVENPORT, Iowa - A dying Iowa man who grew marijuana to treat terminal cancer was sentenced to probation Tuesday, avoiding prison even as he defended his decision to violate the law.

Judge Henry Latham chastised 48-year-old Benton Mackenzie for ignoring the law by growing 71 marijuana plants in a trailer outside his parents' eastern Iowa home. He said growing so many plants would not be legal even in the 23 states that allow medical marijuana, which Iowa does not, and noted Mackenzie had two prior drug convictions.

But Latham said he was using his discretion to grant probation so Mackenzie could receive medical treatment for angiosarcoma, a rare cancer of the blood vessels that has caused large skin lesions on his buttocks. Latham suspended a potential 15-year prison sentence and issued a three-year term of probation instead, a relief to supporters and medical marijuana advocates who packed the Davenport courtroom.

Mackenzie, sitting in a wheelchair, told the judge he felt he didn't have any choice but to break the law. He said the treatment from cannabis oil had made some of his tumors disappear since he was first diagnosed seven years ago. Wearing loose-fitting sweatpants that covered large skin lesions and appearing to grimace at times, he said he was justified ignoring laws that "take away my right guaranteed by the constitution to my life."

"I have lasted seven years on a disease that takes people who don't get treated in two years. And people who go through the traditional methods, they last three years. So basically I have proven the decision I made was the right one, to save my life," he said.

Latham warned that Mackenzie must be substance-abuse free while on probation, and could be sent to prison for violating that term.

"You are a man with intelligence and passion. I hope you can put your efforts to a more constructive use than to continue to violate the laws of this state," he said.

Latham also ordered probation for Mackenzie's wife, 43-year-old Loretta Mackenzie, and his 23-year-old son, Cody Mackenzie. Loretta Mackenzie said staying free will allow her to remain the primary caregiver for her husband, whose condition is worsening.

The case has outraged advocates for medical marijuana, who believe the family should not have been prosecuted.

They were charged following a June 2013 raid on the property of the Long Grove, Iowa, home where they live with Mackenzie's parents. Sheriff's deputies found 71 marijuana plants, growing equipment, drug paraphernalia and a small amount of marijuana in Cody's room.

At trial, Latham barred Benton Mackenzie from testifying about his cancer, noting that a medical necessity defense is not allowed in Iowa.

Jurors in July found Mackenzie and his wife guilty of manufacturing marijuana and related charges. Their son was found guilty of possession, but he maintained his innocence Tuesday.

Scott County Attorney Mike Walton has said he's enforcing state law and noted that Mackenzie's two prior felony drug convictions from 2000 and 2011 make him a "habitual offender." But on Tuesday, assistant county prosecutor Patrick McElyea recommended a sentence of probation after noting Mackenzie's poor health.

The office recently dropped charges of hosting a drug house against Dorothy and Charles Mackenzie, who are in their 70s, stemming from the raid.

Benton Mackenzie smiled as he left the courthouse in his wheelchair, telling reporters he had been prepared for a prison term. He said he will ask his probation officer for permission to travel to Oregon so he can resume treatment under that state's medical marijuana law.

He hopes his case will lead to a more robust medical marijuana law in Iowa, where lawmakers recently voted to allow only the most severe epilepsy patients to use cannabis oil for treatment.

"I hope this is the straw that breaks the camel's back and brings some sanity to lawmakers' decision-making process," he said. "I hope I am the last person who has to go through this."