MIAMI GARDENS, Fla. -

Police announce charges against a 28-year-old man accused of killing an Orange Park man and his grandmother in the woman's Miami Gardens home two weeks ago.

Police charged Reginald Jackson with two counts of first-degree murder, two counts of kidnapping, and two counts of armed robbery. He was arrested Saturday on unrelated charges.

Jackson is accused of killing Annette Anderson, 69, and Tyrone Walker Jr., 20, (both pictured below), whose bodies were found inside her home on July 16.

"I knew her. I cared for her deeply and this loss is extremely personal," said Miami Gardens Mayor Oliver Gilbert.

Police also released two photos of a man who used Anderson's and Walker's credit cards.

"We are pleading with you, if you have any information that can help the officers with the individual that they have not apprehended, please call Crime Stoppers or the police department," said Tyrone Walker Sr.

Police said the man they are looking for was near Anderson's home when he used the credit cards.

Family members said Walker moved from Orange Park to South Florida to go to school, and Anderson was a minister at a local church who held Bible studies at her home on Tuesdays.

Anyone with information on the killings is asked to call Miami-Dade Crime Stoppers at 305-471-TIPS.