Woodbridge Vikings Head Football Coach Karibi Dede talks about the first day back at practice after the stabbing death of senior Kenneth Diaz, a member of the football team. (Brad Horn/The Washington Post)

A small-time drug deal went bad. Instead of handing over marijuana, a young woman pulled out a gun and robbed the would-be buyer of $150. It happened Sept. 12 in a Woodbridge apartment. And nine days later, it led to a homicide — the abduction and stabbing of an 18-year-old high school football player.

That was the story outlined Tuesday by Prince William County police in announcing the arrests of four women and two men, ages 19 to 29, on charges related to the slaying of Kenny J. Diaz, a Woodbridge Senior High School student found dead Saturday in a public park. One of the suspects, 19-year-old Diandra J. Samuels, is accused of murder.

“These encounters were not random and stemmed from drug dealings,” police said in a statement, referring to the robbery and to a confrontation Saturday afternoon between two groups of young people in Woodbridge. After that showdown, Diaz was forced into a vehicle, driven to a park and stabbed, police said.

“You’re not dealing with choirboys here,” including the dead victim, said Commonwealth’s Attorney Paul B. Ebert (D).

According to county police and court papers, a friend of Diaz’s who was looking to buy drugs visited Samuels on Sept. 12 at her apartment in the Glen Arbor complex in the 14300 block of Bellona Road. Samuels allegedly took the young man’s cash at gunpoint.

Diandra Janae Samuels (Courtesy of Prince William County Police)

On Saturday, authorities said, Diaz and some of his acquaintances decided to go back to the apartment complex to confront Samuels about the robbery. “During that encounter, multiple acquaintances of Samuels were also present,” according to the police statement. One of the people with Diaz pulled a pistol, but the gun was taken from him by one of Samuels’s friends, which prompted the group with Diaz to flee. But Diaz “was not able to get away.”

Samuels and several of her acquaintances allegedly abducted Diaz and drove him two miles to Marumsco Acre Lake Park, where he was killed with what police described as “a very long knife.”

Police charged Samuels with abduction, aggravated malicious wounding and using a firearm in the commission of a felony, in addition to murder and armed robbery. Her family members could not be reached, and an attorney who represents her in a robbery case did not return calls for comment.

Five other suspects — Deneen A. Williams, 29; Renee C. Caples, 22; Teena M. Gerbozy, 24; Gregory A. Bonds, 22; and Dominic G. Smith, 26 — were charged with abduction.

Smith, who allegedly took the gun from one of Diaz’s acquaintances, was also charged with being a convicted felon in possession of a firearm.

The killing stunned the Woodbridge High community. Yovana Villagomez, Diaz’s aunt, said her nephew enjoyed sports, especially football, and was a fan of the Washington Redskins. She said he had been an altar boy at Our Lady of Angels Catholic Church in Woodbridge.

“He always had a smile on his face,” said Brandon Williams, a sophomore who had classes with Diaz, a senior. “He would always bring you up.”

Kenny Joseph Diaz (Family photo)

In recent weeks, Villagomez said, Diaz had been talking about going to college. On Monday at Woodbridge High, many of Diaz’s classmates wore red, his favorite color. Students and administrators described the day as solemn and quiet.

“There’s so many questions that’s not answered yet,” Villagomez said of the killing. She said she had never known Diaz to be involved with drugs.

“Nothing at all — not at all,” she said.

At Glen Arbor, a red bench under tall trees is a place where neighbors get together and smoke. Samuels, nicknamed “Dee,” was a familiar face there. She lived with a friend in a top-floor apartment in a three-level, red-brick building, some neighbors said.

“She would play with my son,” said a neighbor who declined to give her full name for fear of retaliation.

Another neighbor said he moved to Glen Arbor because it was an affordable place to raise three kids. But now he wants to leave. “I can’t live here knowing this happened,” he said.

Elsewhere, Claudia Turner, 16, a friend of Diaz’s since kindergarten, said she did not know any of the people arrested in the case, nor were they familiar to any of her friends. Turner said her father coached Diaz in football when Diaz attended Pope John Paul the Great Catholic High School in Dumfries as a freshman and sophomore.

And she said Diaz gave her emotional support several years ago when her father was suffering from kidney disease. She said her mother donated a kidney to her father, so both parents had to undergo surgery.

“He called me. He texted me,” she said of Diaz. “If I didn’t look like my normal self, he would hug me and walk me to class.”

She said she is comforted by the arrests in the case.

“Obviously, no one deserves what happened to Kenny,” Turner said. But knowing the suspects are locked up is “going to help a lot of us with closure.”

Paul Duggan, Jennifer Jenkins and Justin Jouvenal contributed to this report.