Police were not immediately called after a woman and her two children each took bullets to the head in a Des Moines home, a search warrant reveals.

Marvin Oswaldo Esquivel-Lopez, 31, faces three first-degree murder charges after allegedly shooting a small family on the evening of July 16 at a home in the 1000 block of Day Street, just north of downtown Des Moines.

A recently released search warrant offers more information about the day of the killings.

The victims, Rossibeth Flores-Rodriguez, 29, and her children, Grecia Daniela Alvarado-Flores, 11, and Ever Jose Mejia-Flores, 5, were each shot twice in the head, according to the warrant. The woman was found dead in the living room while the children were found near one another in the basement.

Des Moines police on July 16 received an emergency call from Esquivel-Lopez during which he claimed a woman shot two children and that he, in turn, shot her, court records show. He stayed on the phone until first responders arrived.

Police at the scene found a 22-caliber pistol on a living room table, according to the warrant.

Esquivel-Lopez's wife told authorities in an interview that there was a lapse in time between when the shooting occurred and when he notified police, but further details were not provided.

Des Moines police Sgt. Paul Parizek said Tuesday that he could not comment publicly on the possible lapse of time because the investigation is ongoing.

Esquivel-Lopez told police he had an argument with Flores-Rodriguez and then shot her in self-defense after she killed her children, according to the initial police report.

An unidentified witness in the same report told police that Esquivel-Lopez went into the residence after shooting the woman and then shot the children, court documents show. Police said ballistic evidence supports that timeline.

Esquivel-Lopez during his July 18 court appearance said the shooting of Flores-Rodriguez was an act of self-defense. His bond is set at $3 million and his arraignment is scheduled for Aug. 30.

Immigration and Customs Enforcement spokesman Shawn Neudauer said last month that Esquivel-Lopez was in the country illegally and had twice been deported.

Anna Spoerre covers crime and courts for the Des Moines Register. She can be reached by email at aspoerre@dmreg.com, by phone at 515-284-8387 or on Twitter at @annaspoerre. Follow the Register on Facebook and Twitter for more news.