Police said new surveillance video shows the man buy a container of gas a few minutes before the deadly fire was reported at 4 a.m. Thursday.
RELATED: Homicide investigation underway after 2 killed in Tioga-Nicetown house fire
Two people died at a local hospital after being pulled from the second floor of the home, investigators said.
Police have not yet released a possible motive and are still awaiting autopsy results to determine how the victims died.
Anyone with information about the suspect or the fire is asked to contact police.