Authorities have not said whether the boy shot himself on purpose or the gun went off accidentally.
News 5 is not identifying the student.
School officials called 911 after finding the student with a gunshot wound in the bathroom.
The caller tells the operator, "I have a student who shot himself in the bathroom. He has a strong pulse but I need an ambulance."
Jackson Township police say investigators went through the home where the seventh-grade boy who shot himself lives and took evidence from the house.
Chief Mark Brink confirmed that ammunition was found in the student's backpack, but would not give further details.
School to resume Wednesday
Jackson Local Schools will be open Wednesday, according to the district's Facebook page. "Our plan is to open all of our school buildings tomorrow," the post said. "Our goal is to maintain the normalcy of the school day. Please be sensitive to misinformation circulating through social media."
A counseling and mental health team will be available in all school buildings. There will also be additional law enforcement personnel present in all school buildings.
Police said in a news conference Tuesday afternoon that investigators found "distractionary-type" devices in the boy's backpack.
Gina Larkins, who has a daughter in 8th-grade at the Jackson Memorial Middle School, said she was on her way to drop off her daughter who's in 3rd grade when she saw police activity around the middle school.
“I received a phone call from the superintendent that the middle school and high school was on lockdown and all the elementary schools would be closed. I just pulled in waiting to hear further information," said Larkins.
Parents in the area were already on edge this week following the horrific mass shooting at a Florida school.
"I just want to get my daughter and hug her and hold her. I thought it would never happen here but obviously, that is not the case," said Larkins, who was emotional at the thought of what could've happened.
Body armor in book bag
One father whose child goes to the school said he put a piece of armor in his 8th-grade son's backpack over the weekend, in response to the school shooting in Florida.
That father, Don Casey, said a friend who is in support of gun control posted something on Facebook about a man who put regular textbooks in a bag and shot it with a .45, a 9 mm and an assault rifle.
"The handguns didn't go through the first two textbooks. They barely made it through one. I had repainted the shotstop so they gave us this body armor and I put that in my son's book bag."