Police have released a sketch of a man they believe killed a mother and her 8-year-old daughter in the Town Center at Boca Raton mall parking lot.

The robbery and slaying bear striking similarities to a carjacking and robbery that occurred at the mall last August, according to police.

The 30-year-old mother, who was the victim in that case, provided the description for the sketch.

Nancy Bochicchio, 47, and Joey Bochicchio-Hauser, of Boca Raton, were discovered dead by mall security in a black 2007 Chrysler Aspen SUV with the motor still running around midnight Wednesday. The SUV was parked in a merchandise pickup area near the south side of the Sears department store. An undisclosed amount of money was taken.

Police said both mother and daughter had been bound and shot.

In the incident last August, a man with a gun kidnapped a 30-year woman and her 2-year-old son from the Town Center parking lot, bound the woman and made her drive to a bank while he held the gun to her son's head. After robbing her of money, the gunman left them and escaped.

Reached by telephone at her home Friday by Local 10, that victim said she'd been asked not to talk publicly.

At the Town Center mall Friday, shoppers saw a visible police presence in the parking lots. Many had heard or seen news of the killings. Some expressed concerns for their own safety.

Mall management said videotapes from the mall's closed-circuit cameras have been turned over to detectives.

Boca Raton police announced there is a $350,000 reward being offered.

"We've put up a serious reward to encourage anyone with the smallest detail to come forward," Mayor Steven Abrams said Friday. "Our police department is working around the clock to solve this crime."

The suspect in Thursday's attack is described as a 5-foot-10 to 6-foot-tall white or Hispanic male, 18 to 25 years old, with a medium build and possibly a ponytail.

Another unsolved crime that has connections to the same mall is the case of Randi Gorenberg, 52, a mother of two who was last seen leaving the mall the afternoon of March 23. Soon after, she was shot to death and her body was thrown from her Mercedes SUV in a park in nearby Delray Beach.

Authorities have not said whether they believe Gorenberg's death is related to Thursday's killings.

The area that includes Town Center mall is patrolled by police 24 hours a day, said Boca Raton police Sgt. Jeff Kelly.

"You try to plan the best you can for every situation, but how do you plan for random acts of violence such as this?" Kelly said.