NEW YORK (CNN) -- New York City authorities are investigating whether a man shown mugging an elderly woman in a surveillance video is connected to a series of attacks on elderly people this summer.
A surveillance camera caught this clear view of the man who mugged an elderly New York woman on an elevator.
The video, released Monday by the New York Police Department, shows 85-year-old Lillian France accompanied by an unknown man on Thursday in the elevator of an apartment building in Brooklyn's Prospect Heights neighborhood.
When France attempts to leave the elevator, the man grabs her from behind and puts her in a choke hold. She struggles to free herself from his grip but collapses to the floor.
The mugger stole $900, grabbed the woman's cane and ran out of the building.
France is being treated in a hospital for injuries she sustained in the attack, New York Police Commissioner Ray Kelly said at a news conference Tuesday.
Police are asking for the public's help in finding the suspect, described as a black male about 6-foot-1 and weighing 210 pounds. Watch the elderly victim struggle with the thug »
Similar to the attack on France, another elderly victim was recently choked by a man who approached from behind, Kelly said.
Authorities are investigating whether those two attacks are related to a series of similar muggings this summer targeting elderly people traveling alone at night.
The NYPD has dispatched more officers at night throughout Brooklyn to prevent similar attacks.