DULUTH – Infamous head shop owner Jim Carlson asked for a "compassionate release" from his synthetic drug-peddling sentence a year before he was granted clemency by President Joe Biden.

According to federal court filings, Carlson, serving 17½ years after being found guilty of 51 felony counts in 2013, suffers from medical issues including cancer and dental decay. His confinement to an apartment in the Twin Cities along with his twice-weekly check-ins at a Roseville halfway house make his situation "extremely challenging," documents cite him as saying.

Carlson's charges included conspiracy, misbranding drugs, distributing a controlled substance and making illegal monetary transactions. Medical experts testified at his trial that the criminal activity at the downtown store that regularly drew lines of people generated a slew of consequences: It created a public health crisis and dramatically increased narcotic-related police calls, emergency room visits and fatalities.

The Last Place on Earth sold "spice" and "bath salts," and customers testified at trial they caused hallucinations and heart palpitations. After the store closed, St. Luke's hospital said its analog drug-related emergency room admissions dropped from about 75 patients monthly to fewer than four.

Carlson served about nine years of his sentence at a low-security facility in Michigan before he was released by the Federal Bureau of Prisons.

The 67-year-old said in a motion he filed that he must take two buses and walk a mile as part of the journey to the halfway house, describing the trip as "insurmountable" in winter and plagued by "extreme heat and air quality issues" in the summer.

The office of U.S. Attorney Andrew Luger wrote in opposition of Carlson's request, saying that a reduced sentence would not reflect the seriousness of Carlson's crimes.

"For years, he sold destructive analog drugs that caused users to experience harmful side effects and caused severe disruption to Duluth's health care and law enforcement services," the filing reads. "And Carlson made millions doing so."

Carlson didn't return a phone message, but it's unclear whether the number was current. He will be released Dec. 22, according to the Residential Reentry Management field office in Minneapolis.

St. Louis County Sheriff Gordon Ramsay led the Duluth Police Department during the years Carlson's shop sold analogs, or chemical compounds that have properties similar to other drugs. The department tried to get him to stop before tough state laws were passed to curb their spread. The impact on resources, taxpayers and human lives was significant, Ramsay said.

"It was such a challenging issue to address because it was evolving right before us. And the more attention he got, the more business that showed up," he said.

He termed the Biden Administration's decision a "head-scratcher," based on the federal resources that had been devoted to the case and the people who were hurt by his actions.

Don Ness, who was mayor of Duluth from 2008 to 2016, said that what was terrifying at the time drugs were sold was that it wasn't clear "where this was going to lead."

Would the shop become a permanent downtown fixture, he had wondered, with customers traveling hours to wait in line and get high while hanging out downtown?

"It had an absolutely devastating impact on the ability to feel safe and secure in downtown Duluth," Ness said. "He was exporting the harms onto the community for his own profit motive," burdening other downtown businesses and the health care system that had to deal with mysterious overdoses.

"He had no interest in understanding how it was impacting the folks that were ingesting it," Ness said of Carlson.

Surya Saxena is an attorney at the Minneapolis law firm Greene Espel and a former federal prosecutor who led the prosecution of Carlson's case for the Minnesota U.S. Attorney's Office. Carlson's sale of addictive drugs with unpredictable effects was "incredibly heinous and had a significantly negative impact on the community," Saxena said, noting this was his personal opinion as he does not speak for the Department of Justice.

But he doesn't take issue with the commutation of Carlson's sentence, because Carlson had been released to home confinement and is an older man with health problems. "I think he's similarly situated based on his health and age to the other people that were commuted," Saxena said.

State Sen. Grant Hauschild, who represents a portion of Duluth, asked Biden in a letter to rescind the commutation of Carlson.

"By granting clemency to Jim Carlson, the message sent to communities like Duluth is that those who profit from endangering lives can avoid full accountability," Hauschild wrote. "This decision jeopardizes the trust and morale of the law enforcement officers and community leaders who work to make our neighborhoods safe."

The White House said clemency was granted to those who "demonstrated remorse and rehabilitation as well as a strong commitment to making their communities safer."