A 14-year-old Maryland boy armed with an untraceable “ghost gun” opened fire while at an outdoor basketball court Wednesday night, killing one man and wounding three teenagers, prosecutors and police alleged Thursday.

Authorities accused Shilen Wylie of firing approximately 16 rounds during an altercation. He was charged as an adult with one count of first-degree murder and three counts of attempted first-degree murder.

“The allegations are very serious and also very disturbing,” Montgomery County District Court Judge Eric Nee said from the bench Thursday, ordering that Wylie be held without bond.

The night before, according to prosecutors, Wylie had traveled by Metro train and bus from Silver Spring to the Plum Gar Community Recreation Center in Germantown. With him was a friend who had been arguing by text and phone with a 16-year-old.

The pair found the 16-year-old, along with two of his brothers and his friends, on the outdoor basketball courts at the recreation center, according to Assistant State’s Attorney Donna Fenton. Wylie’s friend and the 16-year-old squared off in a fistfight, Fenton said.

“The fight only lasted for several moments before this defendant, armed with a ghost gun, pulled that ghost gun from his waistband and began to shoot,” Fenton said.

The 16-year-old was struck in one knee, Fenton said. His older brother, Axel Trejos, 20, was hit four times. Two others were struck: a 13-year-old who was shot through his shoulder and a 15-year-old hit in the chest and an arm, Fenton said.

Trejos, a 2020 graduate of Clarksburg High School, was taken to Suburban Hospital, where he was pronounced dead, according to arrest records filed in court. The three other victims were taken to different hospitals, and by Thursday afternoon, all had been released.

The lawyer representing Wylie in court Thursday, Lucy Larkins, described him as a straight-A student whose “character and academic achievement” had recently earned him a scholarship to a private boarding school in Pennsylvania, where he was to begin classes Sept. 10. Larkins asked that Wylie be released from custody and be allowed to go to school, “given his incredibly young age, given the fact that he is in school, given that he is a strong student.”

In denying the request, Nee cited the accusations against Wylie.

“Three people [and] the murder victim were shot in this case,” the judge said. “And you had the gun on you when you were taken into custody. Those are the allegations.”

Nee did grant Larkins’s request that Wylie be transferred from the county’s adult jail to a nearby secure facility for juveniles.

A proliferation of “ghost guns” has alarmed police and prosecutors around the country. The weapons are assembled from different parts and with no serial numbers, making them untraceable.

“We have certainly seen ghost gun cases in the county, but none that I can recall that were involved in a homicide,” Montgomery County State’s Attorney John McCarthy said Thursday.

The prosecutor said it was too soon in the case to know how the gun was obtained, including who assembled it. The specifics of the disagreement that preceded the shooting are under investigation, McCarthy said.

Late Thursday afternoon, across the street from the basketball courts, about a dozen relatives and family friends sat outside the home of two of the victims. Several were crying. They declined to be interviewed and said the victims’ immediate family members were too distraught to answer questions.

In Maryland, anyone 14 or older who is charged with first-degree murder must be charged an adult.

Defense lawyers can request that cases be transferred to the juvenile court system, which is geared toward treatment and rehabilitation. That system also has secure facilities and can hold defendants until they reach 21 — a sentence sometimes called “juvenile life,” according to Gary Gerstenfield, a Maryland defense attorney who handles juvenile cases.

Judges examine five factors regarding a defendant in weighing whether to send such a case to juvenile court: the person’s age; physical and mental health; amenability to treatment; the nature of the offense; and public safety.

“Recent case law, however, prioritizes amenability to treatment over the other factors and has given defense attorneys a stronger legal argument in these cases,” said Paul Zmuda, a former prosecutor in Maryland who is now a defense attorney and handles juvenile cases.

Fenton’s presentation Thursday and court filings described how police quickly made an arrest.

Officers were called to the basketball courts for a reported shooting at the recreation center on Scenery Drive near Frederick Road. They found three victims on the basketball court and the fourth nearby and began administering first aid, officials said.

A lookout was put out for the suspect as patrol officers established a perimeter in the area. They quickly spotted two males, police said.

One was Wylie and the second was the friend who had accompanied him to the basketball courts, officials said. Wylie was found to be carrying a 9mm handgun, the same caliber as that used in the shootings, detectives asserted in court records.

Fenton said the 16 bullet casings at the scene will be forensically compared with the gun, which still held three rounds. There was no indication that the person who accompanied Wylie had been charged.

Fenton said that a witness at the scene positively identified Wylie as the shooter. Police termed the case “an isolated incident” that is still being investigated.

Clarence Williams and Julie Tate contributed to this report.