A father and his teenage twins were found dead inside their own house in Orange County, Florida, on Wednesday.

The bodies of Carlo Montiel Infantino and his sister Melanie, both 17, were discovered alongside their dead father Ivan Montiel Roa, 63, after deputies responded to a well-being check.

A concerned neighbor called 911 after not seeing the family for about one week, officials said.

Upon entry to the home, the officers found the siblings already dead in the living room. Both reportedly had multiple stab wounds.

The children's father was discovered dead in the master bedroom.

The tragedy is being investigated as a murder-suicide. Police believe Montiel Roa murdered Carlo and Melanie before taking his own life. 

Montiel Roa's wife and Carlo and Melanie's mother passed away in June. The family was from Venezuela, according to her obituary.

The twins' father worked as a realtor, his Facebook profile indicates. He also owned a construction business that dissolved in late September, the Orlando Sentinel reported. 

On social media, Montiel Roa reposted comments about a 'new world order.'

In a Facebook post from December 2025, he appeared to reference a scene from The Dark Knight: 'Introduce a little anarchy, alter the established order and everything turns into chaos. I am an agent of chaos.'

Democrat state Representative Rita Harris, who lives nearby, told WESH 2: 'It's devastating as a mom, as a human being. Just any type of tragedy like this, but especially when the victims are so young.

'There's a lot that can be done... making sure that we kind of wrap our arms around them and that they have what they need to get through what's going to be, I can imagine the most difficult time of their lives.

'I am also thinking of the first responders and law enforcement officers who carry the weight of what they encounter in service to our community.' 

Frederick Corn, principal of Cypress Creek High School, which Carlo and Melanie attended, also told WESH 2 in a statement: 'I know I speak for our entire Cypress Creek community when I express the extreme grief we feel with this loss.

'Our deepest thoughts and prayers are with family and friends during this incredibly painful time.' 

Details on the exact time of the horrific murders or how the father killed himself were not available as of Saturday. 

The Daily Mail contacted the Orange County Sheriff's Office for updated information.