First responders pronounced Gutierrez-Calzoncit dead at the scene.
"(I) believe this was at a relatively close range," Sgt. Vince Lewis said shortly after the incident.
The couple's two young children were with Gutierrez-Calzoncit when she was killed. They were not physically hurt.
“Later that evening, through the course of the investigation, detectives developed probable cause to arrest [English] for the murder of his ex-wife Blanca,” Lewis wrote in a news alert Wednesday morning, a little more than 24 hours after the shooting.
Lewis did not elaborate on the investigation or explain what led detectives to English.
Officers arrested English without incident and booked him on one count of first-degree murder and two counts of aggravated assault.
It’s not clear how long he and Gutierrez-Calzoncit had been divorced.
During English's initial court appearance Wednesday, the prosecutor said Gutierrez-Calzoncit had been shot eight times. The prosecutor also said English was embroiled in a custody dispute with Gutierrez-Calzoncit and had appeared angry during a court hearing on Monday.
The judge set a $1 million cash-only bond.
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