Montgomery County Park Police Lt. Dave McClintock checks out an MS-13 sign carved into a tree in a wooded area in the vicinity of Veirs Mill and Randolph roads several years ago. (Michael Williamson/The Washington Post)

An 18-year-old was fatally stabbed in a gang-ordered slaying near the Montgomery-Prince George’s county border by assailants who threw heavy rocks down on him as he crawled away from the attack to a stream, according to court records filed in Montgomery District Court on Thursday.

The death of Denis Montufar-Bautista follows two other recent slayings in wooded areas of Montgomery that police have linked to a resurgence of the MS-13 gang. In one of those cases — the killing of a 34-year-old man found in a shallow grave — detectives filed charges this week against four people. The suspects range from 15 to 19 years old.

Montgomery County State’s Attorney John McCarthy raised the issue of gang violence last month. Since then, he said Thursday, he’s come to believe “the depth of the problem is even broader and wider than I ever imagined.”

He said five slayings in the county in 2015 are probably linked to MS-13.

“I don’t think we’ve ever reached this kind of gang violence in Montgomery County,” he said.

In the latest case, one of­
the alleged assailants, Julio­
Rivas-­Rosales, 15, made his first court appearance Thursday — charged as an adult with first-degree murder. Police say that he and others had been motivated by retaliation, because their target had reported being assaulted by four MS-13 gang members who attend High Point High School, in Beltsville, in Prince George’s County.

“This was a revenge murder. It was pre-planned,” Montgomery prosecutor Ryan Wechsler told District Judge Jeannie Cho on Thursday.

The prosecutor said Rivas-Rosales is an MS-13 member and should remain at the county’s adult jail on a no-bond status. He poses a threat to other teenagers if transferred to a juvenile facility, Wechsler added.

John Lavigne, a public defender, responded that, at this point, the charges against ­Rivas-Rosales are only allegations — and he is young and small in stature. “I think he’s 5-2, maybe 125 pounds soaking wet,” Lavigne said, requesting Rivas-Rosales be moved to a secure juvenile facility in Rockville.

Lavigne spoke briefly about his client, saying he arrived in the United States about a year ago from his native El Salvador, lives with his mother and goes to school in Langley Park. Immigration agents have filed a detainer on Rivas-Rosales, an indication they think they have grounds to deport him after any possible sentence has been served.

Cho ordered that ­Rivas-Rosales be moved to the juvenile facility and set his bond at $500,000. Rivas-Rosales’s next court date is set for Jan. 8.

The earlier assault — allegedly at the hands of the High Point students — occurred on Oct. 28. It also was an act of retaliation, police said, because gang members said the victim, also an MS-13 member, had disrespected a higher-ranking member by having sex with that gang member’s girlfriend.

After the assault victim was reported missing on Dec. 16, Prince George’s detectives learned he was last seen with Rivas-Rosales, according to police charging documents. They questioned him about the missing teenager, Montufar-Bautista, this week.

“Rivas-Rosales stated he was dead, at which point he was advised of his Miranda Rights,” detectives wrote. “Rivas-­Rosales admitted to participating in the killing of Montufar-Bautista.”

Rivas-Rosales said he and others used a ruse to isolate Montufar-Bautista — inviting him to come to a trail near Piney Branch Road and New Hampshire Avenue to smoke marijuana, according to the charging papers. The group then walked up the path.

Rivas-Rosales agreed to take detectives to where he had last seen the body.

At 11:10 p.m. Tuesday, detectives carrying flashlights spotted the body — floating in a stream under the Capital Beltway.

Rivas-Rosales told detectives that Montufar-Bautista was stabbed multiple times. He said that he and others also “threw rocks at the victim after he crawled to the stream in an attempt to escape the attack,” detectives wrote in court papers.

As for the earlier assault, police in Prince George’s arrested four High Point High School students, all said to be members of MS-13, according to charging documents. Police said a ­19-year-old, Noe Coreas-Mejia, ordered the assault. He was being held Thursday in Prince George’s County, according to court records.

Prince George’s police on Thursday said the assault is still under investigation but noted that it occurred outside school hours and off school property.

A lawyer listed in court records for Coreas-Mejia could not immediately be reached for comment.