Miami-Dade Fire Rescue is investigating a comment made by one of its firefighters on his personal Facebook page, authorities said.
Thegrio.com is owned by NBC Universal.
Miami-Dade Fire Rescue released a statement saying the post is currently under investigation.
"The post on his personal Facebook page is being investigated by Miami-Dade Fire Rescue. The department's only official Facebook page is: www.facebook.com/miamidadefirerescue."
“I am a private citizen and have the same right to freely express an opinion on any subject that anyone else does. I choose not to embellish or alter the facts as your employer chose to do,” Beckmann said to the website in a Facebook message, the Herald reported.
The Herald reported that when reached by a reporter on Sunday, Beckmann said it was under investigation, and that he couldn't talk to the reporter.
George Zimmerman turned himself in and was booked into the Seminole County jail Wednesday night, after State Attorney Angela Corey announced he faces a second-degree murder charge at a news conference in Jacksonville.
Prosecutors say he fatally shot Martin in the chest during a confrontation on Feb. 26 in a community of townhomes in Sanford, a suburb of Orlando.
Zimmerman says he shot Martin in self-defense and has pleaded not guilty.
The lack of an arrest for more than 40 days after the shooting led to protests nationwide.