MILTON, Wis. -- Two teenagers were arrested on Thursday in connection with the overdose death of a 13-year-old Town of Milton boy last month.

Detectives arrested a 13-year-old boy and a 14-year-old girl early Thursday morning in connection with Alex Aiken's death. The girl is facing a first-degree reckless homicide charge while the boy was arrested for possession of prescription medication.

Authorities said that they believe the Edgerton girl was the source of the OxyContin that was taken by Aiken last month. They think the pills were taken from a relative of the girl who didn't realize any medication was missing.

The boy, also from Edgerton, was arrested at Edgerton Middle School. He took the drugs with Aiken and both overdosed. The teen had previously been reported as having becoming ill while speaking with investigators on the day Aiken was found. Aiken's mother discovered her son on Feb. 9 as she tried to wake him up for school. He was unconscious in his bed.

Aiken's mother, Jenny Bethel, said that she knows who investigators believe are responsible for her son's death and hopes their arrest sends a message.

Bethel continues raising her youngest son and shows him pictures of Alex. The boy is less than 2-years-old and will forever know his big brother from the pictures that he sees growing up. When handed the picture, the boy held it against his face and smiled.

"I never get to see my son. All I have left is my memories and pictures," said Bethel.

Since the day she found her son, she has been waiting for someone to be held responsible.

Investigators received an official cause of death from the Rock County coroner on Thursday

"When we were able to confirm the cause of death, we were confident after interviews as well as statements made by individuals, that we could proceed forward and make an arrest," said Rock County Sheriff Robert Spoden.

"These were groups of friends. These were individuals that knew each other," said Spoden.

Bethel says she understands the pain of the suspects' parents, but said it's nothing compared to what she has to endure.

"Somebody will be charged. I'm happy, but they could get a million years and it still wouldn't be justice enough," said Bethel. "The parents of the kids, you know what, they're probably sad that their kids are being punished, but at least they still can hold their kids and they have to remember that. I don't get to tell my son, 'I love you,' and hear him say "I love you, too, Mom!' I never get to hear that again."

Bethel said that she knows the boy who was arrested and hopes he still grows up to be a good citizen.

Both suspects are being held at the Rock County Juvenile Detention Facility and will appear in court on Friday, authorities said.

Stay tuned to WISC-TV and Channel 3000 for continuing coverage.