A mother is being charged with kidnapping her 12-year-old son after prompting authorities to issue an Amber Alert Monday afternoon, officials said.

Nicholas Johnston, 12, and his noncustodial mother, 48-year-old Sri Johnston, were found in Oceanside at 2:40 p.m., about two hours after the Amber Alert was issued, according to the Long Beach Police Department.

Prosecutors filed kidnapping and child custody deprivation charges against Sri Johnston. She is accused of picking up Nicholas on Wednesday for visitation and not taking him to school the next day, according to the Los Angeles County District Attorney's Office.

David Miller, the boy's father, has full custody of Nicholas, and his mother, Sri, has visitation rights, Miller told NBC4.

Miller realized Nicholas did not go to school and waited for his mother to bring him home. Miller reported his son missing March 7 at 9:15 p.m. Long Beach police then requested an Amber Alert to be issued by the CHP.

Amid questions as to why an Amber Alert was not issued for four days after his alleged abduction, Long Beach police said CHP officials denied the request and said incident did not meet Amber Alert critera at the time of the initial report.

After the DA's office said it was considering filing charges and detectives "provided the DA's Office with new information," CHP issued an Amber Alert, police said.

Miller said he "absolutely" wishes the Amber Alert went out sooner.

"You know you just think about your kid and all the things that are going on right now, mothers and parents harming their children, and not knowing any better," Miller said. "I'm just ... I'm just glad he's back."

Details about how the pair was located were not immediately clear, but police said the boy's father got a phone call on March 6 that his son may be in the Oceanside area.

Sri was taken into custody by US Marshals and was being held in lieu of $500,000 bail. If convicted, she faces a maximum sentence of 13 years and 8 months in prison.

Nicholas was expected to be reunited with his father sometime Monday, Long Beach police said.

Anyone with information is asked to call the Long Beach Police Department at 562-570-9650.

Note: An earlier version of this article listed Sri Johnston as 49 years old according to police, but police later said she is 48 years old.