Escondido street gangs
ATF and Escondido police officers seized 113 guns following an 18-month investigation. Courtesy ATF Los Angeles Field Division

Nearly two dozen defendants have been charged with narcotics and firearms-related offenses following an 18-month investigation into various gangs operating in and around the Escondido area, it was announced Tuesday.

Dubbed “Operation Devil’s Den,” the investigation centered on suspects accused of making firearms — including by using illegal devices that converted them from semi-automatic to fully automatic weapons — then selling those guns.

All but two of the charged defendants have been arrested and some of the defendants have already pleaded guilty to various charges.

The operation — conducted by the Bureau of Alcohol, Tobacco, Firearms, and Explosives and the Escondido Police Department — resulted in 113 guns and 19 machine gun conversion kits seized, as well the seizures of methamphetamine, fentanyl, ecstasy and cocaine.

According to the ATF, undercover officers and confidential informants made 38 controlled purchases of guns and drugs during the operation. The investigation also led to “key evidence capturing an attempted murder,” ATF officials said.

Monique Villegas, special agent in charge of the bureau’s Los Angeles Field Division, said the case highlighted the uptick in “ghost guns,” or firearms that can be assembled via custom kits or 3D printing, as well as an increase in sales of machine gun conversion devices such as “switches” and “drop-in auto sears.”

“What ATF saw 10 years ago with the emergence of the ghost gun phenomena, is now what ATF is seeing with the emergence of machine gun conversion kits,” Villegas said. “The same criminals making and trafficking their own firearms are some of the same criminals trafficking the conversion devices.”

About one-third of the cases will be prosecuted by the San Diego County District Attorney’s Office.

“This operation demonstrates that we continue to grapple with an increase in gang-motivated shootings and the ongoing proliferation of ‘ghost guns’ — firearms that are usually untraceable,” San Diego County District Attorney Summer Stephan said. “The increase in our prosecutions paint a disturbing picture of gang violence on the rise in the county.”

City News Service contributed to this article.