Investigators are still trying to determine what happened after a family of five was found dead in a murder-suicide in Abington, Massachusetts, this week that has left the community in shock.

Authorities have ruled the deaths of two adults and three children a murder-suicide after their bodies were discovered in their home by another family member. Plymouth District Attorney Timothy Cruz said all five victims died from gunshot wounds.

The Discovery

A family member who arrived at the Centre Avenue condo to take the three children to school made the grisly discovery sometime before 7:30 a.m. on Monday, according to authorities.

That family member called 911.

The Family

After the family member called 911, emergency responders discovered the body of 40-year-old Deirdre Zaccardi inside. Upon further investigation, police found the bodies of 9-year-old twins Kathryn and Nathaniel, 11-year-old Alexis and 43-year-old Joseph.

Joseph Zaccardi penned several children's books and sold them on Amazon, according to his Facebook page, NBC News reported. He announced that he had published his third book, "All Mixed Up," in a Facebook post on April 17.

His wife, who worked as an office manager, commented on the post, writing: "I'm so proud of you!"

Relatives issued a statement about the deaths:

"Today our family has suffered an unfathomable loss. As we attempt to make sense of the enormity of this event, we respectfully ask that the media respect our family's wishes to be left alone as we grieve our tremendous losses in private."

The Scene

NBC10 Boston’s Sky Ranger Helicopter captured images of police tape circling the building where the tragedy occurred. Investigators could be seen entering and exiting the building.

Horrified neighbors lingered at the scene, shocked at the unexpected violence. One neighbor told NBC10 Boston she heard suspicious sounds.

"We heard some loud banging, like four noises," said neighbor Heather McNulty, who was watching TV with her husband at the time. "We jumped up and came downstairs and we ended up opening the door."

She looked outside, saw the door to the dumpster swinging, and thought nothing of it until she woke up hours later and learned of the investigation.

The Investigation

The Office of the State Medical Examiner ruled Wednesday that the cause of death for Deirdre Zaccardi and her three children was shooting by firearm, and the manner of their death was homicide. Joseph Zaccardi's cause of death was a gunshot wound and the manner was suicide.

Investigators have not disclosed any further explanation for the shooting.

Cruz said authorities are not aware of any domestic issues in the household but are investigating the possibility.

Community Reaction

The discovery of the bodies left neighbors and community members in shock.

Family friend Debbie Welling said no one saw the tragedy coming.

"Just super fun-loving. Just a normal family," Welling said. "It just proves that anything can happen at anytime. We're just all so devastated. There's no reason. There are no words."

Abington School Superintendent Peter Schafer sent an email to parents on Monday morning about the deaths. He said students at the middle and high school levels were informed by teachers, while younger children were not told about the tragedy.

"Their presence touched so many lives and there are no words to express the sadness we feel," Schafer said in the email.

Students across the school district showed up Tuesday wearing the school color of green on Tuesday in honor of the children who were killed.

Parents say explaining what happened to their kids hasn't been easy.

"I tried to tell her as easily as I could for her to know the truth, because I'd rather have her hear it from me," said Kristen Cary, the mother of a third grader who knew the twins.