The Gwinnett County mother who investigators say was brutally assaulted along with her husband by the couple's two sons claims her sons may have been drugged before the attacks.

In a handwritten letter dated Jan. 2 and sent to Judge Ronnie Batchelor, Yvonne Ervin said her sons are not criminals and should be released from jail.

Christopher and Cameron Ervin have been jailed since their September arrests after allegedly trying to kill their parents by attempting to blow up the family’s Snellville-area home.

“After many conversations, we believe they were given some type of hallucinogen, like PCP, without their knowledge,” the letter stated. “They did not tell us this, however, based on things that were said, we came to this conclusion.”

On Sept. 5, the brothers cut a gas line at the family’s home, drugged their parents with Xanax, placed a candle in their fireplace and waited outside for two hours for an explosion, according to prosecutors. When there was no explosion, the brothers returned to the home and allegedly beat their mother with a rifle and repeatedly stabbed their father, Zachary Ervin.

According to an arrest warrant, one brother told investigators he had been planning the assault for years. In November, the brothers were indicted on charges that include arson, aggravated assault, false imprisonment, kidnapping and robbery, court records showed.

In her letter, delivered earlier this week to Batchelor’s office, Yvonne Ervin said the couple has forgiven their sons.

“After the initial anger, shock, confusion and sadness, we were able to forgive them through the power of God,” the letter stated. “We never stopped loving them.”

Christopher and Cameron Ervin, 22 and 17 respectively at the time of their arrests, are both Shiloh High School graduates. The older brother had completed three years of college. Both brothers planned to enter the military, were raised to love God and had never before been violent, Yvonne Ervin wrote in the letter.

A trial date for the brothers has not yet been scheduled.