This is a 2002 mug shot of Alejandro Chavez-Vasquez taken by Las Vegas Police. He is a person of interest in burglaries in the Portal, Ariz. area in early 2010.

As I reported in my Sunday print exclusive story, the March 27, 2010 murder of Cochise County rancher Robert Krentz that triggered a nationwide outcry about border security remains unsolved a year later.

But as I detail in the story, they've honed in on a man who fits the description of the possible killer — a tall, cross-border smuggler with a violent criminal record. They don’t know for sure if he’s in the U.S. or Mexico — or if he’s dead or alive.

His name is Alejandro Chavez-Vasquez. He is not an official suspect in Krentz’s murder but is a “person of interest” in a series of Portal burglaries in early 2010, say Cochise County sheriff’s officials. Investigators believe there is a link between two of those burglaries and the murder, documents show.

As I dug a bit into Chavez-Vasquez' criminal convictions in four U.S. states, I found an interesting fact — he used a Social Security number that suggests he was born in California when he was arrested in Las Vegas in 2002 on suspicion of attempted sexual assault. The Social Security number appears on all the Clark County, Nev., court documents.

Generally speaking, a person must be a U.S. citizen or legal permanent resident with a green card to have a Social Security number. But it's unclear if the Social Security number he used is legit.

That's because less than a month after he was paroled from Nevada prison on April 15, 2004 (after a two year sentence), he was arrested near Nogales, Ariz. for trying to illegally cross into the U.S., show documents from the U.S. District Court in Tucson.

Chavez-Vasquez was arrested on May 6, 2004. The day before, he had been deported to Mexico through Nogales. The court documents state that he is a citizen of Mexico and in the plea agreement, Chavez-Vasquez testified that he is not a citizen of the United States.

So, clearly by 2004 he was an illegal immigrant who had no legal standing to be in the United States. The only question is — was he at one time a legal permanent resident?