A teenage boy in Claremont was arrested Wednesday night after police said he stabbed his older sister to death with a kitchen knife.
Lt. Mike Ciszek, a detective with the Claremont Police Department, said they received a call about 5:07 p.m., a 911 transfer call from the California Highway Patrol, reporting the attack.
Officers responded to the home along with the
Officers located a 14-year-old boy walking from the residence and determined he was Guerts' brother. After further questioning, he was arrested on suspicion of murder.
It's unclear what motivated the killing, police said.
"The story is kind of shaky," Ciszek said. "We only have his side of the story."
There is a third sibling who was not at home at the time, Ciszek said. The children's parents also were not home during the slaying; one was at work, and the other was out running errands, he said.
"By all accounts, it seems like they were a pretty tight-knit family. It's just kind of a shock."
The Los Angeles County Sheriff's Department's crime scene investigation unit assisted with examining the home for evidence.
As of Thursday morning, the investigation of the scene has wrapped up, and officers are assembling the case, Ciszek said.
Ciszek said the slaying was the first homicide in Claremont since 2009.
"The bottom line: There's no way to put any logic to an illogical occurrence," Ciszek said of the community's efforts to cope with the slaying. But he called on residents to be mindful that a suspect has been detained.
"We don't have some vagabond that's going to kill someone else. The community should be at ease. We don't have an outstanding whodunit."
Staff writer Matt Hamilton contributed to this report.
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