Three people were found shot to death on Wednesday in Arizona in an apparent double-murder suicide. This includes a 5-month-old infant in the case.

Sierra Vista police identified the adult victims as Gerardo De La Torre, 47, and Raquel De La Torre, 30, and said all three had single gunshot wound, according to a Crime Online report.

The bodies were found shortly before noon on Wednesday before a family before and alerted the police. Sierra Vista Police spokesman Corporal Scott Borgstadt said that investigators learned that Gerardo had cancer.

Doctors then told him there was nothing more to be done. A suicide note was found and said that the adults had agreed to a suicide pact and that they were taking the baby with them, according to Borgstadt.

The police spokesman added that the two adults had a single gunshot to the head, while the baby was shot in the chest. Borgstadt then said no further information would be released until autopsies are completed.

Related story: Father Stabs 9-Year-Old Daughter To Death Before Killing Self in Murder-Suicide in Illinois

Murder-Suicide Rates

Studies show that death by murder-suicide is so rare as there is no official nationwide database to monitor how often it happens, according to a Tennessean report.

"Like any health and safety issue, to get a good start on prevention, you need good data," Kristen Rand, legislative director for the Violence Policy Center, was quoted on a report.

She added that the more data that they have across a broader set of murder-suicides, the more successful they will be at trying to prevent them.

Murder-suicides are defined as cases where one person, usually an intimate partner kills a family member them kills themselves within a short period of time, according to the National Institute of Justice definition. Meanwhile, if a case involves the deaths of a whole family, it is referred to as femicide or family annihilation.

An NIJ 2010 report shows that compared to Canada, the United States has three times more incidences of murder-suicides involving the whole family. If compare to Britain, it is eight times more, and 15 times more when compared to Australia.

Meanwhile, an overwhelming number of familicide cases are done by non-Hispanic white men, accounting for 91 percent, according to NIJ, while 88 percent used a gun.

Rand said that 70 percent of the killings involve an intimate partner, and most occurred at home.

"These patterns are repetitive; that's what we're looking for. We want to look for the patterns that repeat themselves," Rand was quoted.

NIJ states that there are certain risk factors when it comes to murder-suicide in families, including prior history of domestic violence, access to guns, threats with increased specificity, and poor mental health or substance abuse.

Meanwhile, it was also reported that economic distress is a factor, but is only among several factors that trigger a man to murder his family. Although personal economics like the loss of a job may be one of several factors, most experts agree that the strength or weakness of the national economy is not related to the frequency of murder-suicides.

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