The body of a person found Wednesday behind a Mankato apartment building was identified as that of 21-year-old Matthew Hoffman of Mankato.

A medical examiner has ruled Hoffman's death accidental and related to the inhalation of an air-conditioning refrigerant, a practice known as "huffing."

Mankato Department of Public Safety Detective Cmdr. Matt DuRose said the police investigation is complete and no autopsy will be performed.

The colorless, odorless refrigerant gas, often referred to by the brand name Freon, can produce a euphoric high when inhaled and can cause irreversible damage to lungs, heart, kidneys and brain.

Hoffman was arrested for theft earlier this year in connection with another huffing incident in which refrigerant was stolen from a Mankato church rooftop air-conditioning unit.

Huffing Freon wasn't the only drug Hoffman used. His sister, Jenny Radke of Mankato, said she and the rest of their family had tried to get help for Hoffman.

Until his death, the family was in the process of having him committed for drug-addiction treatment, Radke said.

Hoffman's life, even at a very young age, saw abnormal ups and downs. At age 6, Hoffman and Radke were split up and placed into separate foster homes. Radke didn't see her brother for eight years.

"It was very hard on him," she said.

He was born in Florida but grew up in the Rochester area. He was a decent student, but an even better athlete, winning a state wrestling title in high school.

Midway through his high school years, however, he returned to Florida to live with his grandparents. To impose discipline on him, and because of family history, his grandparents enrolled him in military academy.

"He did not enjoy the military school," Radke said.

He returned to Minnesota but instead of Rochester, he chose to live in Mankato. He was a student at Rasmussen College, enrolled in computer courses. It was in Mankato where his drug use, Radke said, began to control his life.

On his My Space page, Hoffman kept a blog about his thoughts on life. One entry describes his experience with the drug dextromethorphan, used in over-the-counter cough and cold remedies.

"I find myself under North Kato bridge, listening to Oasis, trying to cry," his Sept. 9 entry reads, "unable to find direction in my life ... Not knowing what I want."