Police say a man is in custody in connection with the attack and sexual assault of a Bronx woman in her building early Thursday morning.

Investigators say the man followed the 23-year-old woman into an elevator at the Andrew Jackson Houses located at East 161st Street in Melrose just after 12:30 a.m.

Once inside, the man tried to choke her until she was unconscious.

Investigators say the woman regained consciousness as the attacker pushed her into a stairwell and forced her onto the rooftop of the building where he proceeded to sexually assault her.

Police say the man demanded her wallet and cash before fleeing the scene.

Charges against the suspect were pending as of late Thursday.

An investigation is onging.