OCEANSIDE, Calif. -- Oceanside police Tuesday were investigating an apparent murder-suicide in which a financially distressed man allegedly killed his sick sister and her dog before taking his own life.

The bodies of Robert Bradford, 56, and 52-year-old Shelly Bradford were discovered in separate bedrooms in a home in the 300 block of Via Metates shortly before 4 p.m. Monday, Oceanside police said in a statement.  The yellow Labrador retriever was found in the room with Robert Bradford, police said.

Officers went to the home after the man failed to show up for a medical appointment. Both individuals were apparently shot to death, police said, noting that a handgun was found near the man's body.

Three neighbors told The San Diego Union-Tribune they were siblings.

Robert Bradford was in financial distress, the newspaper reported, noting that two neighbors confirmed the home was recently sold and the siblings were scheduled to leave Tuesday.

"It appears, based on our preliminary findings, that it is a murder- suicide. But that hasn't been confirmed yet. The investigation is ongoing,'' Oceanside police Capt. Leonard Mata told the Union-Tribune.

Police did not speculate on when the shootings likely occurred.

Neighbor Serena Rodarte told the Union-Tribune that she heard a single gunshot Sunday but mistook it for a car backfiring.

The dog belonged to the woman, according to the newspaper.

Neighbor Mary May told the Union-Tribune that the sister had a kidney disorder and was on dialysis.