Police said the incident was being treated as "workplace violence" and did not appear to have any links to terror.
A man fired from his warehouse job at a Florida company returned to his old workplace near Orlando on Monday and fatally shot five people before taking his own life.
The 45-year-old suspect had a history of misdemeanor criminal offenses but was not linked to any terror organizations, Orange County Sheriff Jerry Demings at a press briefing.
"He was a disgruntled employee that came back to this business this morning," said Demings.
The unidentified assailant arrived at the company that makes accessories for recreational vehicles and campers at about 8 AM (1200 GMT) armed with a handgun and a knife.
He did not use the knife but "shot five innocent people and then turned the gun on himself and killed himself," the sheriff said, adding seven people had survived.
Demings said the incident was being treated as "workplace violence" and did not appear to have any links to terror.
Almost a year ago, on June 12, 2016, 49 people were killed at the Pulse nightclub in Orlando, the deadliest mass shooting in modern US history. At least 58 people were also injured.
"Over the past year, the Orlando community has been challenged like never before," Florida Governor Rick Scott said in a statement.
"I ask all Floridians to pray for the families impacted by this senseless act of violence."