The source tells Action News they are identified as 17-year-old Dante Robinson and 15-year-old Justin Robinson.
Their arrest was announced in a news conference on Tuesday afternoon with Gloucester County Prosecutor Sean Dalton.
"Today we mourn the loss of a young girl named Autumn Pasquale, whose life was tragically cut short before it really began," Dalton said.
The medical examiner has determined that Autumn was strangled to death.
Preliminarily, there were no signs of sexual assault, but the coroner is conducting additional testing.
Around 10:30 p.m. Monday, police were led to a blue recycling bin in front of a house on the 300 block of East Clayton Avenue, not far from the 12-year-old's Clayton home.
Inside, they found Autumn's lifeless body.
Officials tell Action News that Autumn's body was still dressed in the same clothes she had on Saturday afternoon, when she was last seen riding her BMX bike.
Police found the bicycle at the teens' house, which is next door to where her body was found.
Autumn was allegedly lured into the house by the 15-year-old.
"Autumn Pasquale was lured to the juveniles' home; it was for the purpose of obtaining parts for a BMX bike when this incident occurred," Dalton said
Police say Pasquale knew her killers.
Dalton said the teens' mother called them after becoming concerned about a Facebook post, which helped crack the case.
The prosecutor said a decision had not been made whether to charge them as adults, citing the ongoing investigation. However, he said they are strongly considering sending the case to adult court.
The teen brothers are charged with first-degree murder, conspiracy to commit murder, disposing of a body, tampering with evidence and theft. The 15-year-old was also charged with one count of luring.
The teens turned themselves in with their attorney earlier Tuesday, Dalton said.
Autumn's uncle, Paul Spadafora, spoke at the news conference earlier in the day, saying "Our little angel Autumn has reached out to the world in her own special way. She's an angel. She was an angel here on Earth, and she's an angel up in Heaven."
The discovery of her body come just hours after an emotional candlelight vigil was held for Autumn in her hometown.
"This is a very sad day for the Pasquale family," Dalton said earlier in the day. His office led the search with assistance from 20 municipal, state and federal agencies. "Our hearts go out to the family and to all the residents of Clayton who stood together in support of this young girl."
The last known communication from Autumn was in a text message she sent around 2:30 p.m. Saturday.
Autumn, a seventh-grader, would have turned 13 on October 29th.