Manatee County detectives on Wednesday night arrested a 51-year-old woman accused of killing two ex-husbands in Tampa and Bradenton.

Investigators arrested Susan Avalon at her Citrus County home after the Manatee County Sheriff’s Office said she allegedly shot and killed a 54-year-old man who answered the door at his Bradenton home earlier that day.

Manatee County Sheriff Rick Wells said Thursday that investigators believe the killing in Bradenton was part of a “brazen” double homicide that began earlier the same day in Hillsborough County, where Avalon allegedly shot her second ex-husband to death before traveling to Manatee County.

Wells said investigators realized the scope of the case expanded while confronting the suspect at her Citrus County home.

“Detectives let her know that they are there to speak about her ex-husband,” Wells said. “She says, ‘Which one?’”

The sheriff’s office then asked the Tampa Police Department to conduct a welfare check at a home in the 1200 block of East Frierson Avenue, where they found a man dead with multiple gunshot wounds.

Avalon’s arrest follows a shooting Wednesday afternoon at a home in the 7000 block of Chatum Light Run in the Heritage Harbour community. Deputies responded about 2:55 p.m. and found the man suffering from two gunshot wounds, the sheriff’s office said.

Investigators said the victim told deputies the shooter came to his home and shot him after he answered the door. Detectives previously said they believed the shooting was targeted and not a random act of violence.

Wells said deputies were able to speak with the victim before he died and that the man told them the shooter was possibly his ex-wife.

The man later died at a local hospital the same evening, according to the sheriff’s office, which did not release his name, citing Marsy’s Law.

Investigators with the Manatee County Sheriff’s Office said information provided by the victim and evidence collected during the investigation led to the arrest.

Anyone with information about the shooting is asked to contact the sheriff’s office at 941-747-3011. Those wishing to remain anonymous and be eligible for a cash reward can contact Manatee County Crime Stoppers at 866-634-TIPS or submit a tip online.

Times staff writer Emily Wunderlich contributed to this report.