New surveillance video is deepening the mystery around the kidnapping and killing of a 3-week-old baby girl earlier this year in California.

Authorities said Wednesday that the video shows a woman in a black Range Rover SUV closely following a bus carrying the child and her mother.

Long Beach police Lt. Lloyd Cox says the woman stopped the mother and spoke to her about her infant daughter after they got off the bus on Jan. 3.

Authorities say the baby was kidnapped from her home less than two hours later by a gun-toting man who also shot and critically wounded the baby's mother, father and uncle.

The infant's body was found Jan. 4 in a trash bin in Imperial Beach.

Cox says police have no motive.