(NewsNation) — A search team found what they believed to be 20-month-old Quinton Simon’s remains in a landfill, police said during a news conference Monday afternoon.

Chatham County Police Chief Jeff Hadley said that additional testing, including DNA analysis, is being conducted, but they “have every reason to believe the remains are Quinton’s.”

“We have a high level of confidence that those are Quintin’s remains, and we felt that we needed to make the arrest today because that is the right thing to do,” Hadley said.

The Chatham County Police Department also announced Monday that they arrested Quinton’s mother, 22-year-old Leilani Simon, on charges that include malice murder, concealing the death of another person and false statements in the connection with the disappearance and death of her son.

“This is a heartbreaking development for everyone who loved Quinton, for the many people who came to know him after his disappearance and for our department,” Hadley said. “When we first received the call that Quinton was missing, we were hopeful that we would find him alive and unharmed. But as we have been telling you for weeks … all of our evidence pointed to his mother being responsible for his death and disappearance.”

A big question that remains in the case is how Quinton Simon died and if police believe the toddler was dead before his body was put inside of the dumpster.

According to Brett Buffington — the lead investigative reporter at WSAV-TV in Savannah who has been following the case since its inception — Hadley told him its something they’re not ready to discuss.

“I asked the police chief that question yesterday during his media briefing, and he told me that’s just something that he can’t talk about right now,” Buffington said while speaking on “NewsNation Live” Tuesday.

Buffington also said he asked Hadley if there was anything to make him believe this was an accident and that Quintin’s death was just part of a cover-up in a follow-up question. That also could not be discussed.

“The police chief also told me that, right now, he won’t be able to talk about that. It’s evidence in this case — including where the dumpster was that they believe his body was in — they wouldn’t tell us where that is,” Buffington said.

“There’s so much in this case that we don’t have the answers to,” he continued. “That’s likely just because the investigators here are trying to make sure that — here are so many important details that are saved for the day that, obviously now we know, Leilani Simon will face a judge.”

Simon reported her son missing from their home Oct. 5, launching an extensive investigation.

Weeks later, the search became a recovery mission. Hadley told local NewsNation affiliate WSAV in mid-October that investigators had evidence that the child was dead and his mother was the sole suspect.

Quinton’s grandmother had custody of the boy at the time of his disappearance from her house, where Quinton’s mother and her boyfriend were living.

Leilani has other children who, Buffington reports, has been taken by and is in custody of the state.

Leilani was transported to the local jail as she awaits a bond hearing. Officers said they do not anticipate additional arrests in connection with the case.

No additional details about the charges against Simon were immediately available.

Leilani’s bond hearing was supposed to be scheduled for Tuesday afternoon but has been moved to Wednesday morning, Buffington reported.

This is a developing report. Refresh for updates.