A little over a week after a family of four was found dead in a South Anchorage home, police say evidence supports the theory that the boyfriend killed his girlfriend and their two children before ending his own life.

On May 13, the Anchorage Police Department discovered 24-year-old Curtis Young, III; 27-year-old Desiree Leandra Gonzalez; 4-year-old Zaiden Young and 17-month-old Zarielle Young dead in a four-plex on East 74th Avenue.

All the family members had suffered gunshot wounds. The State Medical Examiner’s Office conducted autopsies on the bodies to determine the causes of death.

“While the investigation is still [ongoing], with lab results pending, the evidence supports the theory that this was a contained scene and that this was a murder/suicide,” said APD spokeswoman Anita Shell in a statement Thursday morning.

Police built their case after collecting evidence from the crime scene and interviewing “numerous family and friends,” Shell wrote.

–This is a developing story.