Police say it happened January 2012, on 436 Apple Harvest Drive in the Glengary area of Berkeley County.
Police previously thought David Hutzler, 56, killed his son James Huzler, 9, and then himself. Both victims were found with gunshot wounds inside the home.
At the time, investigators said they found some suspicious materials in the trailer as well.
Now, more than a year later, investigators say they have further physical evidence that shows it's possible David did not kill himself or his son.
Police are asking anyone with information regarding this incident to call Senior Trooper C.S. Maynard at (304)-267-0002 or email at email@example.com.
Anyone wishing to remain anonymous may also contact Crime Stoppers at (301)-267-4999.