A 14-year-old detained for fatally shooting his younger brother Saturday will be released from custody pending further investigation by police.

The Ramsey County Attorney's Office (RCAO) said Tuesday that it requests further investigation of the incident by St. Paul police before deciding if there will be criminal charges in the death of 12-year-old Markee Jones. Family members said the shooting was accidental.

"At this stage in the investigation, there is not sufficient evidence to proceed with a charging determination," Attorney's Office spokesman Dennis Gerhardstein said. "The RCAO will make a charging determination at a future date should additional investigative information become available."

"We've been asked to provide more information, and this remains an active and open investigation with the department," St. Paul police spokeswoman Molly McMillen said.

The 14-year-old was arrested Saturday after authorities were called to the 200 block of W. Stinson Street for reports of a juvenile with a gunshot wound. Markee, 12, died from his wounds at Regions Hospital. Manslaughter charges were pending against his older brother, and his mother, Denisha Hill, asked authorities to release her older son.

Hill said her son, his brother and a cousin were staying overnight at her mother's house, as they frequently did. Several of her mother's 15 grandchildren often frequented the home.

Hill, who lives in Inver Grove Heights, said her mother was away at a religious retreat in Rochester on Saturday. She said an uncle was staying at the house, and that he was asleep when the shooting occurred after the gun was discovered sticking out from beneath a mattress.

Hill described her younger son as "smart and always smiling. He was a happy, basketball-playing kid who loved to be outside with his friends. He was a real boys' boy." Hill started an online fundraiser to raise $30,000 for his funeral expenses, adding that she wants a beautiful ceremony to "send my baby away the right way."

"I want to make sure everything is perfect."

Hill said that her older son has struggled with Markee's death, crumpling to the floor during one of her conversations with him at the Ramsey County Juvenile Detention Center. She said he will likely need therapy and treatment to recover. She's taking time off work because, "I've got to make sure that he's good before I leave his side."

"It's a process," she said. "He's not doing good, but I'm happy he's home so he can grieve with family and I can support him and keep in his mind that we know that it was an accident, we know that he didn't mean to."

"It's so tough," said Hill, who also has a 6-year-old daughter. "This is the hardest thing any parent, mother, anybody can go through. Ever."

Hill wants authorities to hold the person accountable who left the gun at the boys' grandmother's house. It's unclear who that person was, but Hill said it was not her sons or their cousin. Through her grief, she was intent Friday on sending a warning to others in hopes of preventing further tragedy.

"Please, if you own a gun and you've got kids, you're around kids, lock it up if you own it. Do not bring guns into some place where you know there's a lot of kids," she said. "Have respect, don't ever bring a gun to someplace where you don't live. … Even if you got it legal, be mindful."

Star Tribune staff writers Eder Campuzano and Mike Hughlett contributed to this report.