Authorities said Sunday they believe Malcolm Crowell, 22, fled the scene of the homicide in Johnston, Rhode Island, taking 2-year-old Isaih Perez with him.
Authorities issued an Amber Alert for Isaih on Sunday morning.
Conflicting reports emerged over whether Crowell, who police said is wanted in connection with the double homicide, had been arrested.
The local law enforcement source in Rhode Island told CNN that police in Fall River, Massachusetts, had apprehended Crowell.
The Boston Globe initially reported that Crowell had been captured, but then later reported that police were still searching for him. Massachusetts State Police spokesman David Procopio told the newspaper that a man arrested in Fall River on Sunday had no connection to the deaths and missing toddler.
The Massachusetts State Police declined CNN’s request for comment, referring questions about the case to local police in Rhode Island.
The relationship between the suspect and the child is unknown, Johnston Police Deputy Chief Daniel Parrillo said earlier Sunday.