Illinois Teen Allegedly Kills Girlfriend, 9-Year-Old Girl and Child's Father in Home Invasion

An Illinois teenager is accused of killing his girlfriend and two others during a home invasion this week in a Chicago suburb, authorities said.

Byrion Montgomery, 17, has been charged as an adult with first-degree murder, attempted first-degree murder, home invasion, aggravated battery with firearm and aggravated unlawful use of a weapon, according to a press release from the Bolingbrook Police Department.

He is being held on $20 million bail and pleaded not guilty to the charges in Will County court on March 7, CBS News reports. It is not immediately clear if he has retained an attorney to speak on his behalf.

On March 5 around 8:15 p.m., officers responded to a report of a domestic-related home invasion at a Bolingbrook home, where they discovered four people — two adults and two minors — who had been shot, the release states.

Three people were pronounced dead after the attack, police said. Those victims have since been identified as Cartez L. Daniels, 40, Samiya A. Shelton-Tillman, 17, and Sanai Daniels, 9. Relatives said that the youngest victim was Daniels' daughter and that Daniels was engaged to Shelton-Tillman's mother, according to ABC7 Chicago.

A fourth person, a 34-year-old woman, was wounded in the shooting, and was listed in stable condition at a local hospital. She has not been publicly identified.

Investigators said a 3-year-old boy and 14-year-old boy were also inside the home at the time of the incident, but were unharmed.

Montgomery, who police say was dating Shelton-Tillman, was quickly identified as a suspect and was arrested about two hours later close to his home, according to the release.

A neighbor who wished to remain anonymous said her son was playing video games remotely with the 9-year-old victim when she was shot and killed, according to ABC7 Chicago.

"He said he was playing the game, and then he heard gunshots go out, and then he didn't hear his friend anymore," she told the outlet.

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The child of another local resident who rode the bus with the 9-year-old victim spoke with CBS News, saying the tragedy left him frightened.

"I've been feeling unsafe. I've been scared," Camile Valentine's son, Gabriel Alexander, told the outlet. "She was a really close friend of mine."

A motive for Sunday's killings remains under investigation.

The local community held a vigil Wednesday in honor of the fatal victims.

The department said it is working on formal charges with the Will County State's Attorney's Office.

If you are experiencing domestic violence, call the National Domestic Violence Hotline at 1-800-799-7233, or go to thehotline.org. All calls are toll-free and confidential. The hotline is available 24/7 in more than 170 languages.