There are allegations he took on the identity of his dead cousin, Jose Morales, about eight years ago.

A criminal complaint reports the officer's real name as Oscar Ayala-Cornejo. He is 24-years-old and was born in Mexico.

 Oscar Ayala-Cornejo Criminal Complaint

Immigration officials say the real Jose Morales died of cancer and that Ayala-Cornejo stole his identity shortly after the death.

According to the criminal complaint the police officer went to Pulaski High School from 1996 until August 25, 1999 under his real name, Oscar Ayala-Cornejo.

On August 27, 1999 officials say a person using the name Jose Ayala Morales enrolled at Hamilton High School and graduated in 2001. The criminal complaint says officials compared the yearbook photos and they are the same person but with different names.

MPD hired Jose Morales five years ago as a police aide. For nearly three years he's been working as a patrol officer, recently assigned to District 2 of the south side.

According to police spokeswoman Anne E. Schwartz, the officer was arrested by U.S. Immigration and Customs Enforcement on Wednesday. He was suspended that day, following the arrest.

"No matter what kind of background we did we wouldn't have been able to find it, which is unfortunate," Milwaukee Police Chief Nan Hegerty said.

Ayala-Cornejo appeared in federal court Thursday.

He is behind bars and is currently suspended from the police department. He could be deported.

He has a brother on the police force.