Another resident of the condo told police that Stolper told him he was going to pour gasoline down the drain line of the building, ignite it and then padlock the building's fire hoses to prevent firefighters from extinguishing the flames.
Walter Stolper, 72, faces charges of attempted arson and attempted murder.
Walter Stolper, 72, of Miami Beach, is charged with attempted murder. Authorities said that when they arrived at the scene, they discovered Stopler inside the building's parking garage transporting two large containers in a shopping cart.
Stolper, who had meant to place padlocks on the facility's fire hoses to thwart firefighters, had reportedly been served an eviction order.
Luis Diaz, who alerted the condo management, who in turn alerted police about Stolper, told CBS Miami: "He told me he was exhausted of the association and the Jews in the building and he wanted to do something about it".
"Had our officers not investigated this tip as thoroughly as they did, we'd be possibly dealing with several casualties", Ernesto Rodriguez, a spokesman for the Miami Beach Police Department, told The New York Times. The suspect had two gasoline-filled containers with him in the garage and had already dumped several others down a trash chute in the building, police said. Stolper told police he was planning a "small barbecue", Local 10 News, an ABC affiliate, reported.
Detectives last week also located a storage room linked to the defendant with gasoline, sulfur powder, and potassium nitrate.
But the police said Stolper's actions were an attempt to harm and intimidate the people who lived in his building, including Jews.
Authorities said they believe they "averted a tragedy" in arresting Stolper, whom a police spokesman called a "very risky guy".
The ADL added, "Based on available public information about the incident, we urge the Miami-Dade State Attorney's Office to take a hard look at reclassifying and prosecuting this incident as a hate crime".