JACKSONVILLE, Fla. -- After the third fatal police shooting in three weeks, black community activists called Monday morning for a halt to undercover drug investigations and for the mayor to call a town hall meeting on the issue that would involve all parties of all races.

The request for an independent investigation and community meetings comes after Saturday's fatal shooting of an 80-year-old man in an exchange of gunfire with undercover narcotics detectives during a drug sweep of a South Metro neighborhood.

Whether and how the officers identified themselves when property owner Isaac Singletary came out with a gun is still under investigation, as is who fired first.

"He didn't do nothing wrong, but they shot him," neighbor Vanessa Johnson said. "He was just trying to protect his yard, and now he's dead."

At a rally Monday morning, two dozen people gathered in a South Metro apartment complex near Saturday' shooting -- including the New Black Panthers Party and announced candidates in this spring's city elections.

"We have a definite problem with race here," said Jackie Brown, a candidate for mayor. "For too many years -- I mean, at least 30, 40 years -- this has been going on, and nobody's done anything about it."

"We're asking for this city government, for the people in this city to take a stand and have a zero-tolerance policy," said James Evans-Muhammad, a candidate for City Council, said at a Monday morning rally.

Undercover detectives were posing as drug dealers in a reverse sting operation when Singletary confronted them with a gun, Jacksonville Sheriff's Office Chief of Investigations Dwain Senterfitt said.

"You don't expect people to come point a gun at you," Senterfitt said. "At that point, it became about officer safety."

Gary Evans, Singletary's nephew, told Channel 4 that his uncle was territorial and mad about illegal drug activity near his Westmont Street home.

"My uncle asked the officer, which he didn't know at the time he was a police officer, to leave his property and he didn't," Evans said. "Eighty-years-old, and they had to shoot him twice or more in order to subdue him. I'm very upset about it.

According to the JSO, Detectives Donald Maynard and James Narcisse were placed on paid administrative leave while Saturday's fatal shooting is investigated.

The previous Saturday, 18-year-old Douglas Woods was shot at Sabal Palms Apartments on Emerson Street by undercover narcotics officer who said Woods had a gun and tried to rob them. Conflicting statements from witness of that shooting prompted calls last week for an independent investigation.

Five days before that, 65-year-old Harry Shuler was shot and killed by SWAT team members when he refused to drop a gun after he was flushed out of a Northside home where he'd held his mother hostage overnight.