EL PASO COUNTY, Colo. — Exactly five weeks after an 11-year-old boy was reported missing from Colorado Springs, his stepmother was arrested in South Carolina on a murder charge in connection to the case.

El Paso County Sheriff Bill Elder said Letecia Stauch was arrested Monday morning in Myrtle Beach, South Carolina in connection to the disappearance of Gannon Stauch. She had reported him missing on Jan. 27.

She was taken into custody on charges of first-degree murder of a child under the age of 12 by a person in a position of trust, second-degree child abuse resulting in death, tampering with a deceased human body and tampering with physical evidence, Elder said. He called this arrest part of a "rapidly developing and highly complex investigation."

Letecia Stauch is being held without bond at the J. Reuben Long Detention Center in Horry County, South Carolina and will remain there until she is extradited back to Colorado Springs, Elder said.

El Paso Sheriff's Lt. Mitch Mahalko said they are not releasing the information that resulted in Letecia Stauch's arrest, but noted that the investigation has been methodical across multiple states.

"While we have not yet found Gannon, information has been developed that is helping us narrow our search," he said. "As you can see from the arrest, sadly, we do not believe Gannon is alive. Our work is only just beginning."

He said residents in El Paso County will see many law enforcement officials in the county over the coming weeks, and possibly months, as they continue the investigation.

As authorities explained the new development, Gannon Stauch's parents — mother Landen Hiott and father Albert Stauch — stood behind them and held hands with their heads bowed.

Hiott then stepped to the podium. She said while authorities have said that her son is no longer with us, she feels that "he is with us."

"After the stories from people all over the world, he's not only my hero now, but he's the world's hero," she said.

She said she never thought she'd be standing in that position, and called it a nightmare.

"I've had to put trust in people I don't know," she said. "Today I got the worst news and the best news. Obviously we know what the worst news is, but the best news is that justice will be served. And I'll make sure of it. Because my boy did not deserve any of this that has happened to him."

Jacqueline Kirby, spokesperson for the El Paso County Sheriff's Office, read a letter Albert Stauch had written. He described the day his son was born — Sept. 29, 2008 — and how his heart stopped. Albert Stauch said his son's infectious smile and constant laughter impacted everybody he met. He had been looking forward to the boy's teenage years as he became a young man.

His heart stopped again on March 2, 2020, the letter read.

"My little boy is not coming home," it read.

He said that means no more Nintendo games together, taco Tuesdays, smooth-looking haircuts or "G-Man" for this world.

"The person who committed this heinous, horrible crime, is the one that I gave more to (than) anyone else on this planet, and that is a burden that I will carry with me for a very long time," his letter read.

Elder said the investigation has only begun and they will not stop until justice is served.

Few details have been released in the case, but crews over the last few weeks have been searching in the same general area of southern Douglas County as well as northern El Paso County.

Letecia Stauch reported the boy missing from his home in the Lorson Ranch area on the southeast side of Colorado Springs just before 7 p.m. on Jan. 27, according to the El Paso County Sheriff's Office. She told police at the time that she had last seen him between 3:15 and 4 p.m. that day, when he left on foot to play at a friend’s house down the street.

Two days after his disappearance, the El Paso County Sheriff's Office said they were taking "extraordinary steps" to locate him.

In early February, Roderrick Drayton, a neighbor of the Stauch’s, shared a home surveillance video that captured footage of what he said was Gannon Stauch and Leticia Stauch getting into a red truck in the driveway of their Colorado Springs home on Jan. 27, which was the day the boy went missing.

Drayton said the surveillance video showed who he believes was the boy and his stepmother getting into the truck at 10:13 a.m. that day. Leticia Stauch returned, apparently alone, at 2:19 p.m., he said. He said he gave the videos to police to aid in their investigation after learning about the case.

ABC News reported in early February that a spokesperson for the sheriff’s office did not dispute Drayton’s account of what the video showed.

Gannon Stauch's mother, Hiott, and his father, Albert Stauch, pleaded for any credible leads in the case in a Feb. 5 YouTube video on the sheriff office's page.

"I don't have answers for my feelings, other than I'm afraid," Hiott said in the video. "I'm afraid that I'll never hear his voice, that I'll never hear him run and say, 'Mommy!' ... If you're too afraid because you know something — a kid just doesn't disappear and no one sees him. It's not how this works. So if you have anything that's credible — if you're afraid, don't worry about it. Imagine my son, how afraid he is. Imagine how afraid Gannon is."

Horry County (S.C) court records show that Letecia Stauch is scheduled to make court appearances on Tuesday in the case. Click here for the story on her first appearance.