A day or two before Brian Short shot and killed his wife, three children and himself, he bought a Remington 12-gauge shotgun from an Eden Prairie outdoors store.

The information is included in search warrant documents filed in Hennepin County District Court this week as detectives continue to look for evidence in the quadruple homicide investigation. In documents, authorities are asking to look through the family’s cellphone records and other electronics that may have data such as from exterior surveillance cameras at the Greenwood house on Lake Minnetonka’s St. Albans Bay.

The deaths shocked family, friends and co-workers across the Twin Cities, as well as students and teachers at Minnetonka High School, where Short’s children, 17-year-old Cole, 15-year-old Madison and 14-year-old Brooklyn, were enrolled.

On Sept. 10, the South Lake Minnetonka Police Department responded to a welfare check at the family’s home and found it unlocked before discovering the bodies; police say the family was probably shot late on Sept. 7, or early Sept. 8, in their bedrooms by Short, 45, before he shot himself in the home’s garage.

According to this week’s search warrant documents, an employee with access to Short’s e-mail saw an e-mail about his children missing the first two days of school that week and alerted police. An employee told police that Short was stressed because his Excelsior-based business wasn’t going well, according to the search warrant documents. Family friends have also told the Star Tribune he had financial problems and the family was planning to move to a smaller house. And last week, family members said Brian had increasing depression and anxiety over his struggling business and was more absent from family events and boating excursions, but wasn’t feeling better after trying different prescription medications.

Public records show no bankruptcies or state tax liens against Brian Short or his company, AllNurses.com. He was facing a federal lawsuit over anonymous defamatory comments on AllNurses.com but it’s unclear whether it posed much of a legal or financial threat to the business. And in 2014, he told the Star Tribune that the site was drawing 4 million unique visitors a month and he had turned down 50 buyouts in the last 10 years.

However, police have said no evidence has been found leading to a clear motive to the violence. Detectives are requesting data, text messages and other records left in the Short house. They found a receipt from the shotgun, showing it was bought from the Gander Mountain store in Eden Prairie on Sept. 6. Investigators also found two new boxes of shotgun ammunition, with eight rounds missing.

The Minnesota Coalition for Battered Women said the four deaths marked 20 domestic violence homicides so far this year. “This was an extreme final act of domestic violence,” Liz Richards, the group’s executive director, said in a statement. “We cannot wait for horrific homicides like this to propel us into action.”

On Sunday, several hundred people attended the Eden Prairie service for the family of five, recalling positive memories of Cole, Madison, Brooklyn, Karen and Brian Short, and pondering how some questions in the tragedy may never be answered.