This is a partial transcript from "On the Record," July 12, 2006, that has been edited for clarity.

GRETA VAN SUSTEREN, HOST: An American lawyer vanishes in Mexico. Who is this lawyer, and what happened? Is his client list the clue to what happened to him?

Joining us live on the phone is Andres Martinez, a staff writer for The Monitor newspaper.

Andres, who is this lawyer who's disappeared in Mexico?

ANDRES MARTINEZ, THE MONITOR: Hi, Greta. Well, Mario Perera Riveroll is a 43-year-old labor lawyer who has been working, dealing with labor cases in Mexico for about 18 years now. He went missing two weeks ago yesterday, and his family has heard nothing from him so far.

VAN SUSTEREN: Where was he last seen?

MARTINEZ: He was last seen leaving the labor court in Reynosa. It's our sister city on the Mexican side. About 700,000 people live there. And we're here in McAllen, about 10 miles north of the border. About 150,000 people live here.

VAN SUSTEREN: So he's an American citizen. He's licensed to practice in Mexico, and he travels to this city in Mexico to practice law? Is that right?

MARTINEZ: That's right. He became an American citizen in February, even though he'd been practicing — well, he'd been living here on this side for 18 years. And like many businessmen and just regular laborers who travel across the border every single day, there are hundreds and thousands of who do on this part of the border from both Mexico to the U.S. and the U.S. to Mexico.

VAN SUSTEREN: What's the theory, or what do people suspect happened to this man?

MARTINEZ: For the moment, the state police in Mexico have handed part of the case over to the attorney general, the Mexican attorney general, not the state attorney general. And they have no leads. He was seen leaving the labor court about 11:30 AM that Tuesday, the 27th of June. And they have no leads. His car is still missing, a red 2005 Ford Mustang GT.

VAN SUSTEREN: Any personal problems? Any reason why he might just want to sort of, you know, disappear?

MARTINEZ: No, no. His family says that he grew up in Mexico City. They all grew up in Mexico City, came to the U.S. about 18, 20 years ago. His father was an assault lawyer also involved in non-criminal cases, like Mr. Perera is.

VAN SUSTEREN: Any organized group that might want to get him, like an organized crime or someone — or even an individual who has a personal vendetta or reason to get him?

MARTINEZ: No. The police here on the American side have handed everything over to the FBI. The McAllen police here have not gotten involved since they have no jurisdiction in Mexico. And the FBI is just monitoring the case. They haven't mentioned — they've been asked multiple times. We've asked them multiple times about connections to drugs, any of the cartels, and they don't believe that's the case. It would have been a little bit more overt if that was the case.

VAN SUSTEREN: So this man just comes out of court, this lawyer, and just disappears into thin air in Mexico. That's where we are.

MARTINEZ: That's what it seems like for the moment. And for the year, he seems to be first American citizen to have gone missing in Reynosa.

VAN SUSTEREN: All right, Andres. When we get news on this, come on back.

MARTINEZ: Yes, not a problem. Thanks a lot.

Content and Programming Copyright 2006 FOX News Network, LLC. ALL RIGHTS RESERVED. Transcription Copyright 2006 Voxant, Inc. (www.voxant.com), which takes sole responsibility for the accuracy of the transcription. ALL RIGHTS RESERVED. No license is granted to the user of this material except for the user's personal or internal use and, in such case, only one copy may be printed, nor shall user use any material for commercial purposes or in any fashion that may infringe upon FOX News Network, LLC'S and Voxant, Inc.'s copyrights or other proprietary rights or interests in the material. This is not a legal transcript for purposes of litigation.