The man known as "El Diablo" who police believe may be responsible for scores of crimes against Mexican nationals in the Salt Lake Valley may have been working the other side of the law - as an FBI informant.

Rosario A. Alvarado, 23, West Valley, was ordered bound over for trial Thursday on three first-degree felony charges of aggravated kidnapping, one first-degree felony count of aggravated burglary and second-degree felony charges of theft and aggravated assault.Defense attorney Solomon Chacon told 3rd District Judge Lee A. Dever while asking for lower bail that Alvarado had been working for the FBI as an informant.

Chacon indicated Alvarado was talking to the agency about drug cases and was volunteering the information, not being paid for it.

The Deseret News has been unable to contact the FBI agent whom Chacon identified as working with Alvarado.

Salt Lake County Sheriff Aaron Kennard called a press conference after Alvarado's Jan. 27 arrest, asking for victims to come forward. Kennard said at that point they suspected Alvardo was responsible for 50 to 100 additional crimes.

He preyed on illegal immigrants, Kennard said, figuring they would not report the crimes because they want to avoid contact with police. Kennard promised his investigators would not make any inquiries about victims' citizenship status.

Sheriff's office spokesman Deputy Peggy Faulkner said Thursday their detectives, and most likely the sheriff, were not aware of Alvardo's supposed work as an informer for the FBI when he was arrested.

Alvarado was arrested after three men broke into a Kearns home the evening of Jan. 25 while a family was watching the Super Bowl. One of the trio, identified in Thursday's preliminary hearing as Alvarado, shot victim Sergio Rocha in the leg, demanding money and jewelry, according to Rocha's testimony.

They beat Rocha's brother, Cesar, and ordered Sergio Rocha's wife, Maria, and their children into an adjacent bedroom, threatening them at gunpoint.

The men then shoved the wounded Rocha into his truck and eventually drove him to the home of his boss in the 1000 East block of Hollywood Avenue, again demanding to be let in, according to testimony.

The three assailants were scared off by a passing police car, taking Rocha's truck and leaving him on the front porch. Alvarado was arrested two days later, but no further arrests have been made.

Dever ordered Alvarado bound over on the felony charges and denied Chacon's request to lower bail, keeping it at $50,000.