A man suspected in the disappearance of his stepmother was charged Tuesday with stealing her car.
Manatee County Sheriff's Office detectives charged Thomas Fast with grand theft of the 2008 Lexus sport utility vehicle that belonged to Susan Fast.
Susan Fast was reported missing June 29 after her husband, Bruce Fast, returned to his Tara home from a trip to the Bahamas. Her SUV was found in Bradenton the next day.
"We have him driving the vehicle without authorization, and we're inclined to believe he was the last person to see her alive," said Detective Ricardo Alvarado. "He remains a strong person of interest and will continue to be, until we can get more evidence."
Thomas Fast, who is in Manatee County jail on a weapon charge, became a suspect in Susan Fast's disappearance after his father, Bruce Fast, told investigators his son suffered from a mental illness and that he may be involved.
Susan Fast's SUV was found about 3 p.m. June 30 at the corner of Sixth Street East and 11th Avenue East in Bradenton. The vehicle was missing its license plate.
When shown a picture of Thomas Fast, a witness in the neighborhood identified Thomas Fast as getting out of the stolen Lexus and removing the license tag, according to a sheriff's office report. Detectives were still searching for the Florida tag, F3DRO.
The witness said Thomas Fast walked north on Sixth Street East carrying two black duffel bags.
Detectives also aresearching for a black, 30-gallon, plastic garbage can missing from the Fast residence, in the 7500 block of Bird's Eye Terrace.
Investigators have been searching for Susan Fast since her disappearance and fear she may be dead.
"We're still doing what we've been doing," said Dave Bristow, spokesman for the sheriff's office, "just trying to build a case against the stepson - even if we don't find a body - to charge him with murder."
Last week, investigators used information from the location-tracking unit in Susan Fast's SUV to lead them to two more sites to search for the 60-year-old woman: the northern end of the Sunshine Skyway Bridge and gravel pits on Lorraine Road in East Manatee.
"The GPS was helpful," Bristow said. "We've been able to map out the route and search the areas that stood out, such as desolated areas and bodies of water.
"We haven't found anything yet and that's frustrating," he said.
Susan Fast was in the Bahamas with her husband and returned to their home in the Tara community before her husband was to fly back because they could not book the same flight.
Bruce Fast became worried because his wife was not home when he returned, and he noticed items out of place and stains that appeared to be dried blood.
During the investigation, investigators found Thomas Fast's pickup truck June 30 in a shopping plaza near the Tara house.
While deputies were canvassing the shopping center, Thomas Fast, 52, arrived in a taxi.
According to sheriff's office reports, he was barefoot and carrying two black duffel bags.
When Thomas Fast told authorities he was carrying a .22-caliber handgun in his duffel bag, they arrested him for carrying a concealed firearm. Handcuffs, a knife and zip ties were among the items found in the 2006 white Chevrolet pickup truck.
Bruce Fast will have a court appearance at 8:30 a.m. today at the Manatee County jail on the grand theft charges.
Anyone with information on the Susan Fast case can call the Manatee County Sheriff's Office at (941) 747-3011, or CrimeStoppers at (866) 634-TIPS or (866) 634-8477.