MARYLAND HEIGHTS, Mo. – With the porch lights on and the blinds drawn, no one would be able to tell that just 24 hours ago, horror unfolded inside of a home at 12400 Marine Avenue on Thursday night.

Neighbors said they are not only stunned but in mourning.

“I’ve been up all night,” said one woman, who asked to remain anonymous. “It’s very nerve-wracking and for me, it was a reality when they were putting up the crime tape in my yard.”

On Friday, concerned residents wanted to know why and how the innocent lives of Malcolm Mathis II and his toddler son could be taken in such a horrible manner.

The deceased father’s four-year-old daughter and mother-in-law were also badly injured during the gruesome incident.

Our news partners at the St. Louis Post Dispatch reported that as of Friday night, the little girl was awake and talking.

“It’s very upsetting; it’s very scary,” the unnamed neighbor continued. “And we feel for the family and we feel for the children, it’s just really hard.”

Police said Traveon Sims admitted to killing his relatives. Onyai Turner told investigators she helped Sims.

The Post also reported that Sims lived with his relatives who were assisting him but that he had been kicked out a few months ago.

Neighbors said that the Mathis family usually kept to themselves but whenever they were seen outside of the house they were always pleasant.

“We would see each other in the backyard, with the dogs outside, and things like that and they were very friendly and outgoing people,” the woman said.

Barb Berger, who has lived in the Maryland Heights area for 40 years, said she didn’t know the family personally but remembers them moving in over a year ago.

“Right after they came they had a big party for a christening, but other than that it was quiet over there and you didn’t really see them,” Berger said.

Sims has a prior run-in with the police. In 2015, he pleaded guilty to second-degree robbery and was sentenced to five years in prison, however, he was released after about two years.