Jennifer Lynn Morrissey, 33, is charged with criminal homicide, burglary, a gun charge and tampering evidence in the death of Michael McNew, a pharmaceutical manager.
Authorities found McNew dead in a chair in his River Road home Aug. 8, shot in the face, and a bullet casing on the floor nearby, the office said. He'd been killed two days prior and one of his registered guns was missing.
In a statement about the arrest, and court documents, the district attorney's office said they built a case against Morrissey through her cell phone and four confidential informants.
Morrissey and McNew had a prior relationship, but he'd ordered her to move out of his house.
A search of Morrissey's iPhone found user-deleted text messages that showed the two argued on the evening of Aug. 6, hours after McNew's family member last saw him.
McNew texted that he was boxing up her belongings putting them into storage for her to pick up. "McNew further texted that Morrissey was not welcome at the home and that he would defend himself if she came into his home," a probable cause affidavit says.
McNew had two registered firearms in his home, the office said.
Morrissey responded threateningly, typing, "get the gun ready cause I'm coming, I already told you that I'll be there tonight ... guess you're just gonna have to shoot me," the office's statement said.
She also texted: "I'm gonna stab ya" and "I'll gut you like I'm field dressing a [expletive] deer."
When first interviewed by police, Morrissey tearfully blamed her current boyfriend, and said she hadn't been to McNew's house since July 31, and had not resided there for several months, the district attorney said.
Cell phone records, though, told another story, the office said.
Morrissey's phone connected to cell towers near McNew's home between 9:34 p.m. and 9:45 p.m. on Aug. 6, and it auto-connected to a wireless router inside McNew's house at 9:37 p.m. that night.
Police did not find McNew's cell phone, but through cell phone records were able to show it was stationary in his house from 9 p.m. on Aug. 6 to about 1 a.m. on Aug. 7 - when it began moving away from his home.
It last connected to a cell network at 1:34 a.m. Aug. 7 near Yardley Borough ND close to the Delaware River.