The woman who acted as a sign language interpreter at a Florida news conference about the arrest of a suspected serial killer was really signing complete gibberish, authorities said.

Tampa Police Department Chief Brian Dugan briefed a hastily called press gathering Wednesday to announce 24-year-old Howell Emanuel Donaldson III was in custody in connection with four shooting deaths in Seminole Heights.

Standing next to him was Derlyn Roberts, who appeared to be interpreting the chief's statement for the hearing impaired. But her hands were relaying only gobbledygook, police said.

"She showed up and presented herself as being here to provide interpreter services," police spokeswoman Janelle McGregor told InsideEdition.com Monday.

Because the press conference was put together so quickly, the department didn't have time to get an interpreter, McGregor said. Usually, department officials use a local service.

"It's part of something we're looking into," she said. "We want to know how she found out about it, if someone hired her to come to the conference."

McGregor said no crime had been committed.

"We've reached out to [Roberts]," McGregor said, but the woman has not contacted authorities.

Efforts by InsideEdition.com to locate Roberts were unsuccessful.

Texas sign language interpreter Windy Rossi told InsideEdition.com the woman's finger movements didn't mean anything.

About three minutes into the press conference, Roberts was actually signing: "Kill 55 million [unintelligible] please [unintelligible] arrest killed [unintelligible] work school work four one kill [unintelligible] three old two four now I will have ask want [unintelligible] about two times night," Rossi said.

"The deaf community was being left out of important information in their community," Rossi said.

McGregor said the department, from now on, will only use interpreters from their contractor.

"We don't want this to be an issue in the future," she said. "She will not be coming to any more of our news conferences."

It's not the first time a Florida press gathering has been upstaged by a sign language interpreter spouting nonsense.

In September, with Hurricane Irma heading for the state, Manatee County used an interpreter who signed the words "pizza," "bear" and "monster." Officials said they were desperate to find someone who knew American Sign Language and ended up using a county employee who has a deaf brother.

The worker realized quickly that he was in over his head, authorities said.

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