The suspect, identified as 19-year-old Keith Melvin Moses, is in custody, according to the Orange County, Florida Sheriff’s Office.
The shootings took place in the Pine Hills neighborhood of Orlando.
First, the gunman killed a woman in her 20s.
Later, two journalists with the central Florida cable TV outlet Spectrum News 13 were shot by the suspect. They were covering an investigation into the killing of the woman.
One employee was taken to the hospital in critical condition and died from their injuries. The news employees, who were said to be a photographer and a reporter, were in their news van when they were attacked.
The gunman reportedly went to a nearby house and shot a woman and her daughter. The girl, 9, died, while her mother was in critical condition.
"We extend our deepest condolences to all of their families. This is a sad day for our community," the Sheriff’s Office said on Twitter.
The motive behind the shootings remains unknown.
More about: UnitedStates Florida