ST. GEORGE — Investigators Wednesday confirmed that a couple found dead in their home earlier this week died from a murder-suicide. But a day later, neither police nor neighbors had a clear idea of why it happened.

The bodies of Paul Day, 60, and Mary Ann Day, 47, were found in their home near 2000 East and 200 South. Investigators believe Paul Day killed his wife and then himself, based on the evidence found at the scene. St. George police said a "firearm was involved" in both deaths.

A possible motive was not released. St. George police said they had never been called to the house before for any domestic violence-related issues.

"We're all really quite shocked this had to happen," said neighbor Tim Gee.

Gee said he didn't know of any domestic problems with the couple and even saw them out walking together Sunday night.

"They were holding hands and talking, and I didn't see anything wrong," he said.

Some neighbors heard what they thought were fireworks coming from their house about 2 a.m. Monday.