A 45-year-old man accused of killing a 22-month-old boy in Bucks County last year was arrested Wednesday morning in Florida, authorities said.

Shawn Robert Felmey was taken into custody in Melbourne, Fla., by Falls Township police and Bucks County detectives assisted by local police. He faces counts of criminal homicide and endangering the welfare of a child in the Dec. 18 death by head trauma of Brandon Warner.

The boy, who died of head trauma, was most likely thrown or swung by an adult onto the floor of the basement of the Commons at Fallsington apartment where the boy lived with his family and Felmey, authorities said.

Family members told investigators that they saw the boy with unexplained bruises on his head for several months before his death. Authorities said Felmey’s story changed over time, at one point saying the boy could have fallen from his arms onto the floor.

The boy had a twin brother who died last year, reportedly of sudden infant death syndrome, or SIDS.