A Red Cross medical director and Air Force veteran killed his wife, baby son — and the family dog — before killing himself, his Las Vegas neighbors and cops said.

Neighbors said they called police requesting a welfare check on Henry Lunetta, 40, his wife, Karen Michelle Jackson, 35, and their baby Monday morning because the home had been eerily quiet over the weekend.

The Metropolitan Police Department confirmed the deaths were a murder-suicide that had occurred at least a day before they were summoned to the scene.

The Las Vegas Journal-Review said Jackson had just passed a certification test to become a nursing practitioner.

Neighbors said the baby’s first birthday would have been Wednesday.

“It was very shocking to hear,” said neighbor Michael Bernardo. “I know he loved his baby. I know he loved his dog.”

Denise Bernardo said she would have laughed if anyone had suggested Lunetta was capable of killing his family.

“This is deranged. He must have snapped,” she said.

Although the couple didn’t fight in public, neighbors heard complaints from Jackson’s 10-year-old daughter — who wasn’t home at the time of the bloodshed — that Lunetta was controlling.

People who live next door said they spotted a moving truck in front of the home over the weekend and wondered whether Jackson was leaving.

In a July 5 posting to her Facebook page, Jackson said she passed a certification test to become a family nurse practitioner. Her SUV, still parked in the driveway, had a stack of nursing textbooks in the back seat next to the baby’s car seat.

Records indicate Lunetta purchased the home in 2013 and community members said he had a reputation for being a lady’s man before Jackson moved in about a year-and-a-half ago.

His LinkedIn profile and local news reports say he is a medical director for the American Red Cross and neighbors said he was an Air Force veteran.

The American Red Cross confirmed to The Post that he was a medical director for the organization.

A small bouquet of orange and yellow flowers and a small stuffed panda bear were placed in front of the home under a seal from the Clark County coroner’s office prohibiting entry.