REVERE – Police have arrested a Chelsea man accused of killing a 25-year-old woman at a mental health facility in Revere on Thursday and then dumping her bloody body in a church parking lot in Lynn.Suffolk County District Attorney Dan Conley said authorities immediately began combing the streets for Deshawn James Chapell, 27, a resident of a halfway house through North Suffolk Mental Health Association, where victim Stephanie Moulton was employed as a Senior Residential Counselor.The recently engaged Moulton is said to have been viciously attacked and abducted at a residential facility located at 110 Ocean Ave., where Revere police and fire responded shortly after on a report of a fire. Once there, authorities say they found massive pools of blood consistent with a violent assault, but did not find a victim.Shortly after the bloody discovery, Lynn police were alerted to Moulton’s partially clothed body found discarded at St. George Greek Orthodox Church at 54 South Common St. At a press conference later in the afternoon, Conley relayed few details about the murder, saying only that it was an extremely violent assault on an innocent victim.”The investigation is extremely active and has been since the very first 911 call,” Conley said.An arrest warrant was issued for Chapell, charging him with Moulton’s murder, nearly five hours after the gruesome discovery. Massachusetts State Police spokesman David Procopio said Chapell was arrested in the Roxbury section of Boston around 7:45 p.m., as he pulled up to his relative’s home, already swarmed by police as part of a setup. He is expected to be arraigned today at Chelsea District Court.Stunned by the news, Moulton’s aunt, Tracie Novack said she and her entire family are in shock.”She was beautiful and a really good kid,” she said in between tears. “This is just heartbreaking for us.”A 2003 Beverly High School graduate and Peabody resident, Moulton received her Associate’s Degree from North Shore Community College in Behavioral Health and was currently enrolled in additional courses at the school.Novack said Moulton never once mentioned being nervous around anyone at the residential facility, mainly due to respect for HIPAA laws. She instead is said to have exuded happiness whenever she spoke of her position.”I know that she loved her job,” she said. “She had just gotten a promotion and her boss was on maternity leave, so she was in charge and really excited about that. She just really wanted to help people in the medical field? She was a good person.”Novack said she only hopes something good comes out of such a tragedy.”I just talked to her the other day and she was going to take my (16-year-old) son to learn how to drive,” she said. “There’s a reason for everything that happens, but I don’t know what the reason is for this.”