CHICAGO (CBS) — In a 9-1-1 call, Randall Coffland told a dispatcher that he shot and killed his twin daughters, shot his wife, and was going to shoot himself, according to St. Charles Police.

On Friday, officers responded to several 9-1-1 calls of shots fired at 450 S. First St. in the western suburb’s downtown.

“I just shot and killed my two kids and I shot my wife, and I’m going to kill myself now,” Randall told a 9-1-1 dispatcher.

Anjum Coffland — the girls’ mother and Randall’s wife — also called the police. She tells the dispatcher that her husband shot her kids and shot her in the legs.

Saturday afternoon, the Kane County Coroner’s Office identified the two girls as Tiffany and Brittany Coffland, both 16. The girls and Randall were all found dead at the scene with a single gunshot wound to the head.

Responders also found Anjum Coffland inside the apartment with a gunshot wound to the leg. Officers carried her downstairs to a waiting ambulance where she was transported to Delnor Hospital in Geneva.

Evidence technicians recovered two 9mm handguns during a search of the apartment. One of the handguns was found near Randall’s body; the other in a closet inside the residence.

“Our preliminary investigation has led us to believe this was an isolated domestic event,” Deputy Chief David Kintz said on Sunday. “This was a tragic and horrific event. Three lives were lost and another was injured.”

Kintz said St. Charles Police have been working with the Kane County state’s attorney and the Kane County Major Crimes Task Force in the investigation.

A candlelight vigil was held for all three of the victims Saturday evening in downtown St. Charles.

Students, friends and teachers honoring the lives of twin sisters who were shot and killed last night in St. Charles. @cbschicago pic.twitter.com/jGefyp7cpM — Audrina Bigos (@AudrinaBigos) March 12, 2017

An autopsy will be performed by the Kane County Coroner on Monday.