A 17-year-old and his teenage female accomplices bent on revenge killed a classmate with a sword and knife, police say

• Three teens in Florida ambushed and killed a classmate with a sword on October 17, police said.
• One of the trio wanted revenge on Dwight Grant for sleeping with an ex-girlfriend, police said.

Three teenagers in Florida ambushed and killed a classmate with a knife and a sword, local police said.

Over the weekend of October 22, Miramar police arrested a 17-year-old male and two females, ages 16 and 17, NBC Miami and the Sun Sentinel reported.

Police said the trio faced charges of first-degree murder, tampering with evidence, and criminal conspiracy over the killing of Dwight Grant on October 17. The trio has not been named.

Broward County prosecutors said on Tuesday that the trio would be charged as adults, WTVJ reported.

Police believed that the teens targeted Grant after the 17-year-old male discovered that Grant had sex with his ex-girlfriend, NBC Miami reported, citing a police affidavit.

On October 17, the trio gathered at a playground near Grant's home wearing black clothes that they didn't mind being ruined, the police affidavit said.

They then entered Grant's apartment complex and lured him outside his door by calling him at around 7 p.m., police said.

The 17-year-old male grabbed Grant, beat him, and then stabbed him in the neck with a small knife, the police affidavit said. It added that he then stabbed Grant in the chest with a sword held by one of the teenage girls.

The 17-year-old male and the 16-year-old female then carried Grant's body downstairs and hid it in bushes near the apartment block, police said.

At the same time, the other girl removed the blood from the stairwell with cleaning materials she'd brought with her. The trio burned their clothes afterward, police said.

The affidavit also said that the 17-year-old made it clear in text messages before the killing that he wanted revenge.

"Murder will definitely happen soon," the male said in a text message to the 17-year-old female, The Washington Post reported, citing police records.

The male then told the 16-year-old girl that Grant had raped his ex-girlfriend, police said. The Miramar Police Department told The Post: "We have no evidence of any sexual assault."