New York City police are looking for a black man, about 6-foot-1 and weighing 210 pounds, who was caught on tape mugging 85-year-old Lillian France on Thursday in the elevator of an apartment building in Brooklyn's Prospect Heights neighborhood, suspecting that he may be behind similar attacks on the elderly.

Lillian France was probably followed from the bank, where she had withdrawn some $900. Similar attacks, most including choking as in Thursday's assault, were recorded since the end of June in the Crown Heights, Flatbush and Kensington sections of Brooklyn. Most of them involved elderly women who were caught alone in hallways and elevators.

Twelve victims -- one man and 11 women -- have been attacked since late June, police say.

A $12,000 reward has been offered for information leading to the attacker, who left the woman unconscious and spitting blood, her neck bruised from the vicious attack. She was still in hospital Tuesday with high blood pressure.

According to the police, the suspect appears to be wearing headphones during the attack and wears a visor and a T-shirt with the number 38 on it.

In five of the attacks, the victims were choked until they passed out and then robbed, while in two cases, the assailant arrived on a bike.