BOCA RATON, Fla. -

It's hard to fathom what happened to a mother and her young daughter as they wrapped up a holiday shopping spree at the Boca Raton Town Center Mall. But four years later, police are still trying to unravel the mystery of their deaths just hours after a fun-filled girls' day out.

The Boca Raton Police investigation began minutes after a mall security guard found the bodies of Nancy Bochicchio, 47, and her daughter, Joey, four days shy of her eighth birthday, before midnight on Dec. 12, 2007. They were bound and shot to death at point-blank range in Nancy's black 2007 Chrysler Aspen SUV.

Investigators have learned a great deal about the murders since then. Mall surveillance video showed Nancy and Joey entering the mall hand-in-hand. Less than an hour later, the pair left the mall carrying shopping bags.

Police believe Nancy and Joey were carjacked in the parking lot minutes after getting into their SUV. Based on bank surveillance images, detectives said Nancy was forced to drive to a nearby ATM and withdraw $500. During this time she tried to call 911 but was disconnected before she could say anything.

At some point, Nancy and her daughter were bound with clear plastic zip ties and handcuffs. Now police say a pair of goggles was also found on one of the victims -- possibly to inhibit her vision.

swim-goggles

According to police, Nancy broke out of her handcuffs in an attempt to flee, but that bold action cost Nancy and her daughter their lives.

"She was my sister, my friend, my heart," said Nancy's sister, JoAnn Bruno. "She was fighting for that child and begging, begging him to let her go."

Months earlier, in August, there was another carjacking and kidnapping at the same mall. According to police, a gunman attacked and held hostage a 30-year-old woman and her 2-year-old son in the same parking garage at the southwest end of the mall where the Bochicchios were murdered.

"I unlock my car. I put my son in his car seat. I put my bags in and I go put the stroller in the back of the trunk and, when I walk back around, that's when I notice he's in the car," said the alleged victim in that case. "I thought he was going to take me to a house and rape me and murder me."

Investigators do have the surviving victim's memory of her attacker -- his dark, wavy hair, tied back in a ponytail; a distinctive floppy hat with a drawstring; black sunglasses that hugged his face, which had no noticeable hair; and a blue denim button-down shirt.

The Boca Raton Police have released a composite sketch of the man in the Aug. 7 attack. They think the attack may be related to the Bochicchio murders, but they haven't ruled out other possibilities.

The man in the composite is said to be a white man with a dark tan between the ages of 18 and 25. Police say he is between 5 feet 10 inches and 6 feet tall with a medium build. They also think he could have a ponytail.

The Boca Raton Police Service Department says it has tracked down nearly 2,000 leads -- 120 new ones in 2011. Chief Dan Alexander has also assigned three new detectives to the case.