NEW YORK — Police said they have classified the death of beloved vocal coach Barbara Maier Gustern a homicide as the search for her attacker continues.

The announcement on Monday came just two days after authorities released new photos of the suspect, who they said shoved Gustern, 87, to the ground as she was leaving her Chelsea apartment on March 10.

Police released these images of a suspect in the death of Barbara Maier Gustern. (NYPD)

Police said Gustern hit her head on the ground and was taken to Bellevue Hospital for massive bleeding. She died on March 15.

NYPD Chief of Detectives James Essig last week described the incident as an "unprovoked, senseless attack."

Authorities noted that surveillance footage outside the apartment showed a female suspect wearing a black jacket cross the street and push Gustern from behind.

It remains unclear if the suspect intentionally targeted Gustern.

Gustern coached the Broadway cast of "Oklahoma" in 2019 and coached a number of famous vocalists over the years, including Debbie Harry, the lead singer of Blondie.