The revolver was kept on the top shelf of a bedroom closet, too big to fit in the family’s safe.

On Valentine’s Day morning, the parents had gone out for brunch while their two sons played a video game at their Pennsylvania home.

Then the 10-year-old had an idea: What if they acted out the game, but with a real gun?

The boys went into their parent’s bedroom, and the 10-year-old reached for the revolver, the district attorney’s office later said. He pointed the gun at his brother.

What was supposed to be play became a crisis when the boy accidentally pulled the trigger, striking the 12-year-old in the head.

Jere’e Clark, of Harrisburg, Pa., was driving by when the 10-year-old ran outside and screamed for help. The boy had tried to flag down other drivers, prosecutors said, but several refused to stop.

Clark called 911 and tried to save the 12-year-old, but he died of his injuries days later. The boys’ names have not been released.

“If anyone knows their parents please have them contact me,” Clark wrote on Facebook. “I owe them an apology … I tried my best.”

An investigation into the shooting ended Friday, when Dauphin County District Attorney Fran Chardo announced that he would not charge anyone in the case. The boy’s death was accidental, he said, and the parents had taught their children gun safety. They had also stored the other guns in their Swatara Township home in a safe or with gun locks, Chardo added.

Criminal prosecution, the district attorney said, was not in the public interest.

The tragedy continued to reverberate with Clark on Saturday, who wrote on Facebook that the shooting was “the biggest test God has ever sent me.” She had been running errands with her 5-year-old son for a Valentine’s Day celebration when she saw the 10-year-old boy outside in the snow, screaming for help, she told PennLive.com.

Shoeless and wearing shorts, the boy told Clark to call 911. She asked why, and got a chilling answer: “I shot my brother.”

Clark secured her son in her car and followed the boy inside, where his brother looked like he was asleep, she told PennLive.com. She said she started to cry as she followed the 911 dispatcher’s instruction to use a cloth to put pressure on the 12-year-old’s head.

“She was telling me I was doing fine,” Clark said of the dispatcher, PennLive.com reported. “She said, ‘Can you hear the sirens? Help is right around the corner.’”

Police soon took over trying to help the boy until the ambulance arrived.

The district attorney called Clark’s response to the shooting “extraordinary” and said he planned to honor her at a future date.

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