Chen allegedly stabbed her several times in the stomach in her building on 40th Road. She was discovered dead in the hallway just after 7:30 p.m., covered in blood.
Chen sustained cuts to the hand and went to a nearby hospital, where he was placed under arrest.
He is now charged with second-degree murder, tampering with physical evidence and criminal possession of a weapon. A neighbor, identified as Wenxin Zhang, allegedly helped him throw away the clothes and the weapon.
The stabbing ended a long term string of harassment at the hands of the suspect.
Wu ran an employment agency catering to the neighborhood's Asian residents. Chen repeatedly asked for a job, and the victim repeatedly told him she couldn't help.
Along with the nine orders of protection, the last filed just five days before the murder, Chen reportedly had a prior arrest for assaulting her.
Authorities have also charged Wenxin Zhang, the landlord of the building, in connection with the murder. Police said she was seen on surveillance tape cleaning up blood and throwing away evidence.