FARMINGTON — The San Juan County suspects arrested as part of a year-long sting operation had long criminal histories and several recently were released from jail.

Local and federal law enforcement officials announced in Albuquerque on Friday that 23 Four Corners region residents were arrested for illegally selling guns as part of an investigation called "The Farmington Project."

The suspects arrested were repeat felons, according to the U.S. Attorney's Office.

"Repeat offenders are the biggest problem we have," San Juan County Sheriff Ken Christesen said. "They clog the system and they keep law enforcement busy investigating crimes they are doing over and over again."

In the last year undercover agents bought 32 guns and methamphetamine from San Juan County suspects who had felony convictions and couldn't have firearms. Many of the guns had scratched off identification numbers, U.S. Attorney Kenneth Gonzales said in a prepared statement.

The Albuquerque Field Office of the Bureau of Alcohol, Tobacco, Firearms and Explosives and the Farmington Gang Unit investigated felons with firearms. The gang unit is part of an anti-drug task force comprised of officers from The San Juan County Sheriff's Office and Farmington and Bloomfield police.

"When you are buying guns and drugs undercover it's the most dangerous job in law enforcement," Christesen said. "The work (the undercover officers) did was dangerous and I think they put together good cases, so I'm very thankful."

Fourteen of the 23 suspects were arrested in an enforcement operation July 17.

The U.S. Attorney's Office identified 13 of the 23 people charged with crimes. Four of the remaining suspects are fugitives and six are in state custody pending transfer to federal custody and have not yet been publicly identified.

Sixteen of the 23 suspects were charged with being felons in possession of a firearm, which carries a maximum penalty of 10 years in prison. The other suspects are facing state criminal laws.

"The federal firearms laws are some of the most valuable tools in the federal law enforcement toolbox," Gonzales said in a prepared statement. "The felon in possession statute enables federal law enforcement agencies to work with their state and local partners to target repeat offenders for federal prosecution so that they can be removed from their communities while they serve significant prison sentences."

Christesen said sending more than a dozen "career criminals" away for up to 10-year prison sentences will have a significant effect on local crime.

"When you arrest the worst of the worst, you'd like to see them be gone for a little bit," Bloomfield Police Chief Mike Kovacs said. "For them to be out for that length of time, we don't have to be in fear of them committing those crimes they commit over and over again."

Local law enforcement officials have long lobbied to get to work with federal agencies, which can lead to lengthier prison sentences if the suspects are convicted in federal court.

"The Farmington Police Department welcomes federal assistance in apprehending and removing career criminals from our communities," Farmington Police Commander Cliff Washburn said in a prepared statement.

Weldon Delaney, 29; Juan Pablo Mata, 39; Rene Mata, 49; Rrturo Cervando Quintana, 32; Angela Marie Sandoval, 46; and Darin Richard Scott, 33, are all Farmington residents who were arrested as part of the operation, according to the U.S. Attorney's Office.

Scott has felony convictions in San Juan County dating back to at least 2002. He most recently was arrested June 15 in Durango, Colo., for his part in the high-profile burglary there where a trailer filled of property was stolen from a family hospitalized after their house exploded.

Sandoval was released from jail in February after she was convicted of credit card fraud.

Juan Mata has a criminal and civil history with local police. He has filed civil lawsuits against the Farmington Police Department and individual officers.

Mata also was arrested in April 2010 for conspiracy to sell methamphetamine during another operation that involved local and federal law enforcement agencies.

Daniel Emilio Armenta, 47, Derek Barr, 26, Thomas Gonzales, 43, and Sandra Valencia, 26, are Aztec residents who were arrested.

Barr was released from the detention center in April after he served 30 days for a probation violation stemming from a larceny crime he was arrested for in 2010.

Emilio Garcia, 45, and Henry William Garcia, 47, are Bloomfield residents who were arrested.

Henry Garcia was charged with felony larceny on June 15 and is yet to appear in court on those charges.