Background
Costello was born in Orlando, and attended Graceland University, from which he graduated in 1970.
Costello was born in Orlando, and attended Graceland University, from which he graduated in 1970.
He then attended the University of Iowa, receiving his Doctor of Dental Surgery in 1974.
Previously, he represented the 26th District, which included southern Flagler County and northern Volusia County, stretching from Ormond Beach to Deltona, from 2010 to 2012. After graduation, Costello joined the United States Air Force, from 1974 to 1977, serving as a Captain, and then returned to Florida in 1977, settling in Ormond Beach and practicing dental medicine. He was elected to the Ormond Beach City Commission, where he served from 1999 to 2002, and then was elected Mayor, serving from 2002 to 2010.
In 2010, following the inability of State Representative Pat Patterson to seek re-election, Costello ran to succeed him in the 26th District, which included southern Flagler County and northern Volusia County, stretching from Ormond Beach to Deltona.
Advancing to the general election, Costello campaigned on "creating jobs for Floridians in renewable-energy research development and manufacturing," and was opposed by Tim Huth, the Democratic nominee and the former Deputy Superintendent of Volusia County Schools. When the state"s congressional districts were redrawn in 2012, Costello opted to run in the newly-created 6th District, which stretched along the east coast of the state, including Flagler County, southern Putnam County, Saint Johns County, and northern Volusia County.
He faced former federal prosecutor Ron DeSantis, restaurant executive Craig Miller, Saint Johns County School Board member Beverly Slough, Jacksonville City Councilman Richard Clark, William Billy Kogut, and Alec Pueschel in the Republican primary. Costello campaigned on his support for "individual and "states rights"" and clashed with DeSantis, who attacked Costello in mail advertisements and television advertisements as a "tax and spend" liberal who voted in the legislature to give undocumented immigrants in-state tuition, for spending increases, and for an internet sales tax
When State Representative Dave Hood, Junior. decided to run for a seat on the Volusia County Circuit Court rather than seek re-election, Costello jumped into the race to succeed him in the 25th District, which is based in eastern Volusia County, including Ormond Beach, Daytona Beach Shores, Portuguese Orange, Ponce Inlet, and New Smyrna Beach.
He campaigned on promoting job creation, increasing protection of the environment, and preserving home rule of local governments, as his work was not done in elected office, declaring, "I never intended to get out of politics. I"m looking forward to going back to work." Costello ended up defeating Bickford by a wide margin, winning 59% of the vote.