The mother of a 4-year-old Washington boy whose body was found along an interstate has been arrested on suspicion of his murder, authorities said Friday.

Janet Garcia, 27, was arrested on suspicion of first-degree murder, second-degree murder, and first-degree assault of a child in connection with the death of son Ariel Garcia, officials said.

Garcia, of Lynwood, was arrested and charged with making a false statement to a public servant in Clark County earlier in the day.

Ariel Garcia was reported missing by family members on Wednesday afternoon. The Washington State Patrol sent out a mass alert to the public about his disappearance the next day. 

The little boy's body was found in Pierce County along Interstate 5 on Thursday, according to the Everett Police Department. 

"I am completely heartbroken for the family and friends of Ariel Garcia and they will remain in my thoughts as they grieve this unbelievably tragic loss," said Everett Mayor Cassie Franklin in a press release.

Janet Garcia told police her son fell out of bed and hit his head when they were visiting a friend, local outlet KING 5 reported, citing Clark County District Court documents.

When the friend returned to their home, they found a substantial amount of blood, and Janet and Ariel were missing, according to KING 5. Garcia allegedly told police that she tried to take her son to a hospital after the reported fall, but the wait was too long. She then allegedly said she dropped the 4-year-old off at a friend's house in Seattle.

According to court documents, police interviewing Janet Garcia saw what appeared to be splatters of blood on her shoes and shirt. Throughout the questioning, Janet Garcia's answers were "inconsistent and difficult to follow" but she continued to say her son had fallen and hit his head, police said.

The Snohomish County Medical Examiner has yet to determine the cause and manner of death.

It was not immediately clear whether Garcia had an attorney who could speak on her behalf.