The first of the three happened in August, when a high-voltage transmission line in Cabot was intentionally brought down.
"Although no injuries resulted from this act, the placement of the line created a risk to the community," FBI spokesperson Kim Brunell explained.
Investigators have released a clue: a 250-foot cable recovered near the scene.
It's believed the cable, which has a diameter of one-half inch and an attached 15-inch eyebolt, could have been surplus, salvaged or stolen.
On September 29, a fire was intentionally started at Entergy Arkansas's Keo substation.
The message "YOU SHOULD HAVE EXPECTED U.S." was found on a metal control panel outside the station.
October 6, 10,000 First Electric Cooperative customers near Cabot were without power after lines on two poles were cut just before 7:30 a.m.
Investigators believe a tractor with an extendable arm and circular saw blade was stolen from a nearby property and used to cut the lines.
Investigators believe the suspect(s) have knowledge of electrical matters and the ability to operate a large tractor. There is also a $25,000 dollar reward for information leading to an arrest.
If you have any information, contact the FBI at 501-221-9100.