MESA, Ariz. -- Police are searching for a father and two children who have been missing since May 2013.
Christopher Creech, 38, 11-year-old Krissanna Creech and 9-year-old Shayanna Creech were last seen on May 26 in the area of Extension Road and Main Street.
Police were not aware of the situation until Sept. 15.
They may be in Colorado where the family used to live but investigators also have reason to believe they could be in Northern Arizona or Mexico.
Relatives who have not heard from Creech in several months are concerned about him and his daughters.
"They're with their biological father who they've been with for years so you would think that in general they would be comfortable and hopefully safe with him," said Detective Steve Berry with the Mesa Police Dept. "We don't have any real indication that he would want to harm them or anything like that."
Christopher has a history of irregular behavior and may be emotionally unstable, according to Mesa police.
"He does have some sort of criminal past that caused him to have a warrant for his arrest." said Det. Berry. "We're much more concerned with the welfare of the girls and him for that matter than we are for the warrant."
The family may be traveling in a blue 2000 Dodge Ram 1500 with Arizona plate AMX-4983.
Anyone with information about Creech or his children should call the Mesa Police Department.
"We have spoken to the biological mother of the two girls," said Det. Berry. "The family has been split for several years. Mom lives in another location out of state and she has not had any contact with the family in years so she was not able to provide any additional information."
Click here to see the missing persons flyer from Mesa PD