SCOTTSDALE, Ariz. - The sister of 39-year-old Jason Fairbanks described a loving and fun big brother who grew up into a devoted family man.

Laura Fairbanks spoke with 12 News over the phone, but declined a formal interview, saying she was still too distraught over a horrific incident that Scottsdale police say was a murder-suicide that left her brother, his wife and two kids dead.

A concerned coworker arrived at the Fairbanks home on Friday to discover all four had been shot.

After further investigation, detectives determined Jason shot and killed his family, including a 3-year-old girl and 9-month-old boy, before turning the gun on himself.

Laura said her family members, all on the East Coast, are shocked and saddened over the incident and said Jason never spoke of any problems or troubles. She said the couple were a source of tremendous support for her when she was going through some rough times.