Police cars and emergency equipment can be seen at the Villages at Rockville, a retirement community where police say a man killed his wife and himself in Rockville. (Dan Morse /THE WASHINGTON POST)

At 9:30 a.m. Monday, Albert Ballard, 80, arrived at a nursing home in Rockville to visit his wife, Sandra, 74, as he did most every day. He signed in and was given a badge so he could move around the place.

Minutes later, shots were heard from Sandra Ballard’s room. The couple, married for more than four decades, were dead.

Montgomery County police classified the case as a murder-suicide, and officials said Albert Ballard shot his wife and then himself.

Two law enforcement officials with knowledge of the case and a family friend of the Ballards’ said that Sandra Ballard had recently suffered an injury causing paralysis and that Albert might have become despondent about their situation. One family friend, who did not want to be named because she did not have the family’s permission to speak, described the shooting as “an act of love.”

Sandra Ballard was staying in a rehabilitation section of the facility, the Village at Rockville, often referred to as the National Lutheran Home, on Veirs Drive, about two miles west of Interstate 270.

“She was not herself anymore,” one of the law enforcement officials said.

It was unclear whether Sandra Ballard knew beforehand what her husband was planning on doing, police said. Officials said detectives will search Albert Ballard’s home to look for a note.

“Our thoughts and prayers go out to the family members affected by this tragedy,” said Lawrence Bradshaw, chief executive officer of National Lutheran Communities & Services, which owns the home.

Detectives recovered a gun from inside Sandra Ballard’s room. Albert Ballard was living at the house the couple bought for $28,000 in 1967, along Parkvale Road in Rockville, according to property records and police.

A woman who answered the door at the Ballards’ home on Monday politely declined to answer questions. Neighbors of the Ballards’ also declined to speak, saying they were honoring the family’s wishes not to comment.

The retirement home has about 350 residents, said Officer Rebecca Innocenti, a Montgomery police spokeswoman. About 215 people live in the main facility and 135 live in small houses on the campus.

Residents include those receiving continuing care and rehabilitation services. Sandra Ballard was receiving “sub-acute rehabilitation services,” according to Bradshaw. He did not elaborate.

Bradshaw called the Village at Rockville a safe facility and said “we are taking every precaution necessary to keep it that way.”

Courtney Malengo, a spokeswoman for National Lutheran Communities & Services, said visitors are required to sign in before receiving a badge, which Albert Ballard did regularly.

“He visited her daily,” she said. “Because he saw her pretty much every day, there was nothing that gave us cause for concern.”

Staff researcher Jennifer Jenkins contributed to this report.