(CNN)When federal agents busted into Anthony Todt's Florida home to arrest him in a fraud case, they found the decomposing bodies of his wife and children.
On Tuesday, a grand jury charged him with four counts of capital murder and one count of animal cruelty for killing the family dog, Florida State Attorney Aramis Ayala told reporters.
He now faces the death penalty, Ayala said.
"I can't imagine the pain and agony (the family is) going through, but we are going to absolutely do all that we can to make certain that justice is served. And as we go through this process it is my hope that they're able to find some semblance of peace in this process," she said.
Todt was arrested in January after confessing to killing his 42-year-old wife, Megan Todt, and their three children -- ages 4, 11 and 13 -- as well as the family dog, Breezy.
Deputies discovered the bodies while serving a federal warrant connected to an investigation into Todt's Connecticut physical therapy business. Investigators believe the family had been killed some time at the end of December, Osceola County Sheriff Russell Gibson said in a news conference last month.
"Myself, I cannot understand what would cause a person to commit such evil and horrendous acts," Gibson had said.
A family member had asked for a well-being check
Todt ran the physical therapy business out of two locations in Colchester, Connecticut, but spent weekends at the Florida home, where his family lived, authorities said.
Investigators interviewed him in late November after the Department of Health and Human Services raised suspicions that he was billing Medicaid and private insurance for services he had not provided to his Connecticut patients, an affidavit shows.
"When specifically asked if he routinely billed for services that he didn't provide, Todt replied, 'Yes,' Todt elaborated that he started 'adding stuff' when he performed the billing and randomly chose the patients that he submitted extra claims for payment for," according to the affidavit.
Todt had said he would plead guilty and investigators asked him to have an attorney contact them as soon as possible, according to the affidavit. But they never heard from anyone in November and December.
On December 29, one of his relatives asked Osceola police to check on the family, "because she had been told that (the Todt family) all had the flu and she had not heard from them in two days," Gibson said last month.
But the deputy who visited the home received no answer at the door, and having no cause to enter the house, they left. The sheriff said the killings could have already happened at that time.
Deputies returned on January 9 after attempting to contact Todt about the federal investigation.