FORT LAUDERDALE, Fla. (AP/WFLA) – Authorities say a 30-year-old man who was invited to live on a family’s property in northeast Florida has been charged with the “brutal” premeditated murders of their two young sons.

The boys’ mother found their bodies on Wednesday.

Mark Wilson Jr. was arrested late Thursday night.

State Attorney R.J. Larizza said during a Friday morning news conference that Wilson “attacked those two kids without mercy.”

Sheriff H.D. “Gator” DeLoach says investigators found the murder weapons — a knife and hammer.

“The sick monster responsible for Tayten and Robert’s brutal murder was arrested last night,” DeLoach wrote on Facebook. “Unfortunately, Robert and Tayten were the ones who suffered whatever was going through Wilson’s twisted agenda. As a parent, the murders of Robert and Tayten are an unimaginable loss to a family. I can’t begin to understand the anguish their parents are suffering.

“My sincere hope is that the death penalty is pursued in these senseless murders,” DeLoach continued.

The boys were 12 and 14 years old. The family had moved from Polk County to Melrose, which is south of Jacksonville, 16 days ago to be closer to family, the sheriff said. He did not say which city in Polk County.