At least three members of the violent MS-13 gang kidnapped and killed an Annapolis teen who went missing in 2017, according to federal authorities.

One man, David Sosa-Guevara, who authorities described as an MS-13 leader in New York, acknowledged his role in 16-year-old David Rivera’s death as part of a sweeping guilty plea in federal court where he and two associates admitted to participating in nine homicides, the U.S. Attorney’s Office for the Eastern District of New York said in a recent news release.

In a separate case, two other men, Manuel Erazo Alvarado and Erick Guillen Pleitez, have been charged with murder in aid of racketeering in an Aug. 29, 2017, killing, an indictment unsealed Thursday in Maryland federal court says. The indictment does not name Rivera, but the date of the killing listed in the indictment is the last day the 16-year-old was seen and the day cited in the New York news release as the date of Rivera’s killing.

The indictment, which was filed under seal in February, appears to redact the names of other alleged MS-13 members who are accused of participating in Rivera’s killing.

According to the federal prosecutors' release, Sosa-Guevara and another MS-13 member moved to Maryland from Long Island to “avoid law enforcement.” Once in Maryland, they connected with a local clique of the transnational gang and learned of “a plan to kill a rival gang member.”

“On August 29, 2017, Sosa-Guevara drove the other gang member to a park outside of Edgewater, Maryland, for him to participate in the Rivera murder,” the news release said. “The victim was brought to that location by other MS-13 members, attacked with machetes and killed.”

Rivera disappeared during an approximately two-month stretch where two other young, Hispanic residents also went missing from Annapolis, according to news reports.

The remains of the two others, 21-year-old Jenni B. Rivera-Lopez and 17-year-old Neris Bonilla-Palacios, were discovered that fall in parks or wooded areas around the Annapolis area. In both cases, police said, they had been brutally killed. Authorities arrested and prosecuted members of MS-13 in the slayings.

Rivera’s body was not found until last year, on June 7, almost seven years later, according to the news release.

Attempts to reach Rivera’s relatives were unsuccessful.

Federal court records do not list an attorney for Erazo Alvarado. Reached by phone, Jose Antonio Molina, an attorney for Guillen Pleitez, noted that his client is presumed innocent.

“We’re looking forward to defending him in this matter,” Molina said. “It’s very, very early in the proceedings and the government has yet to provide us with any discovery materials from which we can understand what the government says Mr. Guillen Pleitez’s role is.”

An attorney for Sosa-Guevara did not respond Tuesday to an emailed request for comment.

The indictment in Maryland’s federal court does not detail Erazo Alvarado’s or Guillen Pleitez’s alleged roles in Rivera’s death, and instead uses boilerplate language about MS-13 that federal prosecutors regularly include in racketeering cases.

Composed primarily of immigrants from El Salvador or their descendants, MS-13 traces its roots in America to the 1980s, when it began in Los Angeles as a means for Salvadorans to band together for protection against larger Mexican groups, federal prosecutors say. It quickly spread across the country and to Maryland, where it is in Anne Arundel, Baltimore and Prince George’s counties and Baltimore City, among other jurisdictions.

MS-13 operates in “cliques” throughout its territory, including in the Annapolis area, according to court records. Each clique had a leader and a second-in-command, who kept in touch with the top lieutenants of the gang, either in America or El Salvador. MS-13 makes money by extorting or taxing businesses and residents, primarily in Hispanic communities.

The gang also beefs with other groups and violently disciplines members who fall out of line, regularly planning and carrying out attacks against perceived rivals or detractors, federal prosecutors say.

“MS-13, in the area of Anne Arundel County, Maryland maintained rivalries with, among others, the 18th Street Gang,” prosecutors wrote in the indictment.

Erazo Alvarado, 46, had an “active arrest warrant” through the International Criminal Police Organization, better known as INTERPOL, for “homicide/firearms and gun trafficking and extortion in El Salvador” when the Annapolis Police Department’s SWAT team raided his apartment in Annapolis in November 2017 during a drug investigation, according to court documents.

Annapolis Police found a loaded handgun in a bedroom where Erazo Alvarado had barricaded himself, according to charging documents. Detectives wrote that he said the gun and ammunition belonged to him.

An FBI task force officer authored a federal complaint charging Erazo Alvarado with possession of a firearm in furtherance of a drug trafficking crime, saying the drug probe was related to gang activity.

Informants told investigators that Erazo Alvarado was a high-ranking MS-13 member who went by the nickname “Castigo,” or Punisher, and regularly carried a gun, according to the officer’s affidavit. Officers noticed several telling tattoos on Erazo Alvarado when they arrested him, including “MS-13″ inked on his right arm.

He kept a ledger in a notebook of subordinates in the gang who sold marijuana for him, according to the affidavit. He told investigators he sent a $160 to El Salvador, which the officer interpreted to be a “tax” intended to MS-13 to “fund gang-related activities.”

In state court, Erazo Alvarado pleaded guilty to illegal possession of a regulated firearm and was sentenced to two years in prison.

In federal court, he pleaded guilty to possession of a firearm in furtherance of a drug trafficking crime. A judge sentenced him to five years in federal prison, the mandatory minimum for that crime. He was released from custody in December, according to federal prison records.

Baltimore Banner reporter Justin Fenton contributed to this story.