NEW YORK (CBSNewYork) – Police are investigating two attempted rapes in Park Slope, Brooklyn.

It’s unclear if the same suspect was behind both incidents or if they were unrelated.

Around 4:30 a.m. on Sept. 8, a man allegedly followed a 26-year-old woman into the lobby of her building near Garfield Place and Prospect Park West.

Once inside, police said the he exposed himself and grabbed the woman. She fought back, and he took off toward Prospect Park West.

Then around 7 p.m. on Sept. 16, a man allegedly grabbed a 17-year-old girl’s buttocks near Carroll Street and Eighth Avenue.

Police said the suspect threatened to sexually assault the victim.

When a Good Samaritan confronted him, he allegedly kicked the man and ran away.

The girl was able to escape unharmed.

Police described the suspect in the first incident as black, approximately 5 feet 10 inches to 6 feet 2 inches tall, with a medium build, last seen wearing a gray hooded sweatshirt.

Anyone with information about either incident is asked to call NYPD’s Crime Stoppers hotline at 1-800-577-TIPS (8477) or 1-888-57-PISTA (74782) for Spanish. You can also submit a tip via the Crime Stoppers website, by Tweeting @NYPDTips or by texting a tip to 274637.