A suburban Chicago teenager pleaded not guilty Tuesday in the fatal shootings of his 17-year-old girlfriend, a 9-year-old girl and the child's father.

Byrion Montgomery, 17, appeared before a Will County judge in Joliet. Montgomery is charged as an adult with multiple crimes, including first-degree murder, attempted first-degree murder and home invasion.

He has been jailed and bail is set at $20 million. The Will County State's Attorney's Office said he would be appointed a public defender.

BOLINGBROOK SHOOTING: TEEN SUSPECT KILLS GIRLFRIEND, TWO OTHERS IN HOME INVASION

The shooting in Bolingbrook, about 30 miles west of Chicago, was reported about 8:15 p.m. Sunday. Montgomery was arrested about two hours later.

Seventeen-year-old Samiya A. Shelton-Tillman, 40-year-old Cartez Daniels, and 9-year-old Sanai Daniels were pronounced dead at the scene. Tania Stewart, 34, was shot but survived. She was in stable condition Tuesday at a hospital.

Illinois Fox News graphic

Byrion Montgomery, 17, has pleaded not guilty in a Bolingbrook, Illinois, triple homicide case. (Fox News)

Two boys ages 3 and 14 were in the home at the time but were not harmed.

Police have said Shelton-Tillman and Montgomery dated.

AFTER LIGHTFOOT LOSS, CHICAGO MAYORAL FINALISTS SPLIT ON CRIME STRATEGY

"The violence that occurred is something no one should ever have to endure or worry about," Bolingbrook Mayor Mary Alexander-Basta said in a statement. "My deepest condolences go out to the family and friends of the victims, and my prayers are sent to the victim still in the hospital."

Relatives of the victims told WLS-TV that Sanai was Cartez Daniels’ daughter and that he had been engaged to Stewart, who is Shelton-Tillman’s mother.

Reed Silva, Cartez Daniels’ stepmother, told the Chicago Tribune that he worked as a carpenter.

CLICK HERE TO GET THE FOX NEWS APP

"He could do anything, mathematically," Silva said. "He loved his family. He loved everybody. He tried to do anything he could for anybody. He was making life better for him and his kids and his family."