The FBI is asking the public to help find three fugitive siblings who allegedly shot at a Florida police officer during a high-speed chase, then robbed a bank in Georgia and wrote an ominous text message to their mother.

The first shootout happened shortly after 7 a.m. Tuesday when an officer attempted to pull over the trio for speeding along state road 54, north of Tampa.

During the five-mile chase Ryan Dougherty, 21, and his sister Lee Grace E. Dougherty, 29, and half-brother Dylan Dougherty Stanley, 26, reached speeds of up to 100 mph in their 2006 white Subaru Impreza, which had a New York license plate. They fired multiple rounds at the Zephyrhills, Fla., officer and eventually ruined one of his tires.

The siblings escaped, and police later found 20 "high caliber" shell casings along the route. The officer was not injured.

That same day, the trio traveled to southern Georgia, more than 200 miles away from where they had been pursued. Police believe that at 12:19 p.m. the brothers entered Certus Bank in Valdosta, Ga., dressed in black and wearing masks. One was wearing a cap, large sunglasses and a white bandanna.

Surveillance video caught three sibling robbers on tape as they fired rounds at Certus Bank in Valdosta, Ga.

The siblings stole an undisclosed amount of money after firing two rounds in the bank with what appeared to be an AK-47, according to commander Brian Childress, Valdosta Police Department spokesman. Nobody in the bank was injured.

Now the bandits are on the run, last seen in an older model white, 4-door sedan.

So far the siblings only appear to have communicated with one relative -- their mother. Tobin said she received a text saying, "There's a time for all of us to die."

Search for Fugitive Florida Siblings Intensifies

Plans are now underway to expand a digital billboard campaign showcasing photos of the siblings, according to FBI Atlanta field office spokesman Stephen Emmett. With the new "multi-state effort" the billboards, currently only in Florida, will soon be placed throughout the Southeast.

Police recovered weapon parts in a women's bathroom trash can at Tampa International Airport at 4 a.m. on Wednesday, but Tobin says they haven't determined whether the items belonged to the trio.

Ryan Dougherty had cut off his GPS monitoring bracelet one day prior to the Florida police chase after being sentenced to 10 years probation for sexual battery. He has 13 felonies on his record, Pasco County Sheriff spokesman Doug Tobin told

Ryan Dougherty's siblings also have a troubled past.

Lee Grace Dougherty has been charged with five felonies and six misdemeanors including a pending case involving a hit and run from May 17. Dylan Dougherty Stanley has been charged with marijuana possession.

The brothers had been living in the tiny town of Lacoochee, Fla., about an hour north of Tampa, for the past three years. Ryan's girlfriend, who has not yet been indentified, also lived with them, Tobin said. Their sister, Lee Grace Dougherty, had been living in Orlando with her boyfriend but stayed with her brothers for a few days before the bank robbery.

Pasco County Sheriff Chris Nocco had tough words for the brothers and sister during a Tuesday press conference.

"If you're a suspect and you're watching this right now, turn yourself in peacefully. Because once we find out who you are, the next thing you're going to see is our SWAT team coming down and kicking in your door, and grabbing you," he said. "I promise you, we will not tolerate this in Pasco County."

There is no indication at this time as to where the three fugitives may be heading.

Law enforcement officials have repeatedly said the suspects should be considered armed and dangerous. If you see them or their car, call the FBI at (404) 679-9000 or the Valdosta Police Department at 229-293-3145. If you wish to remain anonymous you can call 229-293-3091.