Daniel Rosen, a senior State Department official arrested last month for soliciting sex online with a minor, was reportedly arrested again Sunday night in Washington, D.C., and charged with an earlier crime of voyeurism after police searched his cellphone. And he is only the latest in a long string of government employees to have been accused of crimes against children.

Public records and reports reviewed by The Daily Beast show that at least 22 current and former local, state, and federal employees have been convicted of crimes ranging from distributing child pornography to conscience-shocking acts of violence against infants. The crimes have occurred over the past decade, with many of the cases coming in the past four years. Experts say the numbers are likely far higher and may not be thoroughly documented by law enforcement agencies across the United States.

There is a veritable rogues gallery of sexual predators from the ranks of local law enforcement to the diplomatic corps. Their crimes usually involve some online component, either distributing graphic images or using text messaging and chat rooms to lure victims.

At the State Department, where Rosen worked, a senior technology project manager was arrested in 2012 and accused of 10 counts of possessing child pornography. The same year, a former special agent with the Bureau of Diplomatic Security was sentenced to seven years in prison for possession of child porn, including some 30,000 images contained on computer equipment in his house. And in 2008, a Foreign Service Officer was sentenced to 20 years in prison for possession of child pornography and admitted to videotaping his sexual encounters with girls while working abroad as a consular officer.

At the CIA, the former station chief in Algeria was sentenced to more than five years in federal prison for drugging and raping a Muslim woman and for illegally possessing a firearm while under the influence of cocaine. Authorities also discovered child pornography on his laptop computer, though no charges were filed for that offense. At the Homeland Security Department, six now ex-employees are doing time for crimes including possession of child pornography, soliciting sex with minors, and human sex-trafficking. And in 2011, a U.S. Army lawyer and West Point graduate pleaded guilty to “forcible sodomy with an infant” and making and distributing violent images of child abuse.

Crimes against children aren’t limited by government agency or the profession of the offenders, who hail from the military, local law enforcement, and federal departments. “Child porn within our government agencies has reached crisis level,” Lori Handrahan , a researcher of child sex abuse cases, wrote in a recent blog post . Handrahan, who has documented other cases in and out of government, says large numbers of men are downloading child pornography frequently from their work computers.

Precisely how many government employees have been convicted on child pornography charges is difficult to assess because official reports don’t distinguish by employment category. And many of the most frequently cited government reports on child sexual crime rates haven’t been recently updated.

But federal statistics show a rising trend in child pornography and exploitation cases. Between 2007 and 2012, more than 11,447 defendants were convicted in federal courts for offenses related the sexual exploitation of a minor, according to a Justice Department report . “These crimes have ranged from production of obscene visual depictions of minors engaged in sexually explicit conduct to receipt, distribution, possession, and/or production of child pornography to the direct physical, sexual abuse of a minor.”

In 2010, the Justice Department released the first-ever National Strategy for Child Exploitation Prevention and Interdiction, which aimed to assess the dangers from child pornography, online enticement, and other crimes against children. It found that between 2005 and 2009, there was a 432 percent increase in child pornography movies and files submitted to the National Center for Missing & Exploited Children, which attempts to identify victims.

“Although documenting the precise quantity of child pornography is difficult, it is evident that technological advances have contributed significantly to the overall increase in the child pornography threat,” the strategy report found. From 2005 through 2009, it said, U.S. Attorneys prosecuted 8,352 child pornography cases, “and in most instances, the offenders used digital technologies and the Internet to produce, view, store, advertise, or distribute child pornography.”

The label “pornography” arguably doesn’t capture the depravity of some of the crimes committed against children. In 2012, a Ganby, Connecticut, police captain was sentenced to 10 years in prison for possessing and trading videos that “horrifically depicted children being sexually abused by adults,” according to a U.S. prosecutor. Among the images the former cop sought from fellow traders were those of babies being bound and tortured, officials said.

Also in 2014, the former acting director of cyber security at the U.S. Department of Health and Human Services was convicted for his participation in a child porn ring that included images so violent and disturbing that even veteran investigators said they were shocked by what they saw. A federal prosecutor said the employee used his technical expertise to navigate anonymous computer networks frequented by child porn peddlers.

Cases of violent child abuse in the United States have mirrored recent revelations from an organized abuse ring in the United Kingdom featuring senior members of the British government. Shocking cases of crimes against children went unreported or covered up for decades. As The Daily Beast reported Friday, the potential key witness in the ring, who was himself allegedly a victim as a schoolboy, fled Britain and now lives in the United States.

The international dimensions of child pornography and violence haven’t escaped the FBI, which last week helped to take down an alleged porn kingpin in South Africa. The accused was reportedly arrested at his home in Grahamstown, near the country’s southern coast, and had 16 hard drives, a laptop, and video and still cameras. FBI agents are said to have discovered the network after seven people were arrested in the United States using Web sites designed to coax children into performing sexual acts while surreptitiously being videotaped.

The FBI is seeking to extradite the man because most of the victims were in the United States.

—Brandy Zadrozny contributed research.