Hialeah Police Detective Carl Zogby said the incident began when Pedro Vargas, 42, set fire to the cash inside his apartment, drawing the attention of apartment complex managers Italo and Camira Pisciotti.
Vargas allegedly shot the couple and then started shooting at passersby -- killing six people in all.
"This is probably one of the worst shootings we have had ever in Hialeah," Zogby said.
"My mom was dead the moment that she was shot and my dad still had a pulse when I got to him," Shamira Pisciotti told WTVJ-TV, Miami.
Vargas held two hostages for about 8 hours before SWAT team members killed him and rescued the two hostages unharmed.
"Now starts the investigation, how and why this happened," Zogby said.