An elderly woman was killed during a home invasion in southwest Houston.

Houston police said a couple at a home on Sanford near Mullins heard their dog barking about 9 p.m. Thursday.

The 84-year-old husband opened the back door to let the dog out and a man forced his way inside, pushing the husband to the ground, police said.

Detectives said the man kicked the husband in the head.

The wife tried to intervene and the suspect beat her with his hands.

The wife, Margaret Marie Gage, 82, was taken to Southwest Memorial Hospital, where she died.

The husband was treated at the scene.

"It's an apparent robbery as the motive," Sgt. C.E, Elliott said.

The suspect forced the husband to show him where valuables were kept, police said. He took off with several items including a diamond ring, a sapphire ring, a blue topaz ring and a necklace, investigators said.

Detectives said they believe the couple was targeted and may have been followed home. Police said they were checking surveillance video from businesses the couple visited earlier in the day to see if the suspect was caught scoping out the couple on camera.

"They targeted them," said the victims' daughter, Loa Glenn. "I think someone saw them and followed her home because they went straight to (Margaret Gage) and wanted her jewelry."

The suspect was described as tall, dark and slender. The husband suffers from dementia and Alzheimer's disease and has had trouble giving police a detailed description of the suspect.

Officials said they do not know if the man got away on foot or in a vehicle.

"I would like him to be caught so he can't do this to anyone else," Glenn said.

The killing has shaken Elliot, who has been a homicide investigator in the Houston Police Department for 21 years.

"When you get that age, you should be able to be safe in your own home," Elliot said while choking back tears.

Anyone with information is asked to call the HPD Homicide Division at 713-308-3600 or Crime Stoppers at 713-222-TIPS.