The 40-year-old then apparently turned the gun on himself, Tallahassee Police Chief Michael DeLeo told reporters.
Beierle’s motive for “this heinous act” is not known at this time, he added.
Mr DeLeo said his officers responded to reports of the shooting at Tallahassee Hot Yoga within “three, three-and-a-half minutes”, by which time Beierle was already dead.
A number of other victims received gunshot wounds, while one person was pistol-whipped.
“There are indications that several people inside fought back and tried to not only save themselves but other people, which is a testament to their courage,” Mr DeLeo said.
Two of the victims remain in hospital, while three others have been treated and released.
Tallahassee Mayor Andrew Gillum – who is currently running as the Democratic candidate for Florida governor – said he would be cutting short a campaign event and returning to the city.
“No act of gun violence is acceptable,” he said. “I’m in close communication with law enforcement officials and will be returning to Tallahassee tonight.”