Charges were filed Tuesday against the 13-year-old accused of opening fire in an Indiana middle school classroom, hitting a teacher and a 13-year-old girl, who suffered critical injuries. The Hamilton County Prosecutor's Office filed a petition Tuesday alleging the suspect is a delinquent child, but he won't be tried as an adult, CBS Indianapolis affiliate WTTV reports.

He's accused of shooting teacher Jason Seaman and 13-year-old Ella Whistler on May 25 at Noblesville West Middle School. Seaman has been credited with helping to stop the attack.

Under Indiana law, a 13-year-old can only be tried as an adult if a murder was successful.

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"In this case, due to the heroic and extraordinary efforts of many people, including teachers, a school nurse, the Noblesville Police Department School Resource Officer, and many other first responders and medical providers, thankfully, Jason Seaman and Ella Whistler survived," said prosecuting attorney D. Lee Buckingham, II in a press release. "This blessing results in this matter remaining in the juvenile justice system under our current laws, a result which will, I am sure, be very troubling and unsatisfying for many people."

Seaman's family issued an emotional letter on Tuesday, which was obtained by WTTV. Seaman's parents, Bob and Kristi Seaman, say there "have been so many acts of kindness and so many notes of encouragement and prayers" since that day they can't even begin to thank everyone.

Seaman was treated at a local hospital after being shot in the abdomen, the hip, and the forearm.

The family of Ella Whistler, 13, said Monday that she had been shot seven times, including in her face, neck and upper chest.

Ella received "emergency, life-saving surgery" at Riley Hospital for Children in Indianapolis following the shooting, and she is currently in stable condition, her family said.

"She continues to make progress but faces a long road to recovery. She will remain an inpatient at Riley Hospital for the foreseeable future," the family said.

An online fundraiser has been established to raise money toward her medical expenses. The site had raised more than $89,000 toward a $90,000 goal by Monday evening.

Authorities have said the boy was armed with two handguns when he entered Seaman's classroom and began shooting. The school is about 20 miles north of Indianapolis.

Indiana law protects the privacy of juveniles accused of crimes and limits what information can be released. Buckingham said authorities cannot confirm the suspect's identity, age or describe the alleged offense until a charging petition is filed.