The brothers are accused of setting fire to a mobile home on Riverview Drive in Westville, a blaze that spread from a bed inside the trailer, according to the Gloucester County Prosecutor's Office.
A police officer on patrol discovered the fire at 12:47 a.m. Saturday, the Prosecutor's Office said, and the Westville and National Park Fire Departments responded to extinguish it.
The trailer was incinerated, according to the Prosecutor's Office, but no one was inside, and no injuries were reported.
Investigators subsequently discovered a video on Anthony Pettolina's Facebook account that showed the brothers inside the trailer before it burned - and also showed one of them lighting a fire, the Prosecutor's Office said.
Both brothers were arrested at a nearby family home around 6:30 a.m. Saturday and were being held on $100,000 bail.
Prosecutors did not provide a copy of the video, and did not say which man allegedly set the fire or what the motive may have been.
The video could not be seen on Anthony Pettolina's Facebook page Saturday. Attempts to reach relatives of the brothers were unsuccessful.