MESA, Ariz. -- Mesa police said they have located Sean Kramer, 12, who was nowhere to be found when police discovered his mother dead inside their Mesa apartment.

Kramer was supposed to visit an aunt in Los Angeles on Sunday, but he never arrived, according to police.

Police said they responded to a welfare check Friday afternoon at the Mesa apartment complex and found the boy's 44-year-old mother dead. Police identified her as Nancy Vreeland-Ballan.

For several hours, officers said they did not know where Sean was.

But after television reports, a friend called authorities and said he was with them.

Police are still trying to sort out all of the details of this case.

The medical examiner is still determining the cause of Vreeland-Ballan's death.

Anyone with information is asked to call the Mesa Police Department at 480-644-2211.