A WIFE allegedly shot a woman she believed was having an affair with her husband in an ambush that ended in a murder-suicide, police in Pennsylvania have said.

Radnor Township Police said Jennair Gerardot, 48, meticulously planned the grisly killing on Monday night that left 33-year-old Meredith Chapman dead, the New York Post reported.

“[Gerardot] went to great lengths to disguise herself,” Police Superintendent William Colarulo said according to the Philadelphia Inquirer.

“She wore a wig, and took a train from Delaware to Radnor. She broke into the victim’s house, and cleaned up the glass so the victim didn’t realise someone was in her home.”

Police said Gerardot ambushed Ms Chapman around 7pm when she walked in the door.

The jilted wife then turned the gun on herself.

The alleged assailant’s body was found near the kitchen, not far from Chapman’s, news station WACU reported.

A wig and other clothing were found in a bag inside the house, police said.

Gerardot’s husband reportedly alerted authorities that they may find his wife inside the crime scene.

“There were emails and text messages indicating what [Gerardot] might do,” Supt Colarulo told WACU.

On her personal web page, Gerardot is described as a “confident, creative, highly driven businesswoman” who loves animals and travelling.

Her husband, Mark Gerardot, worked at the University of Delaware, where Ms Chapman was previously employed before starting a new job as assistant vice president at Villanova University.

Mr Gerardot was the creative director at the university and reported to Ms Chapman.

Ms Chapman also unsuccessfully made a bid for a state Senate seat in Delaware in 2016.

Her husband, Luke Chapman, was also involved in politics as a former Newark city councillor.

“It’s cleared as far as we’re concerned,” Supt Colarulo said.

“You had a man who’s married who’s having an affair with this other woman. His wife knew that. This was a calculated attack.

“She broke into the house. She was lying in wait, and then she shot herself. There were emails and text messages indicating what she planned to do. Detectives are still sorting that out.

“We believe the husband was in the area under the belief that he was meeting the other woman for dinner, and when she didn’t show up, that’s when he got concerned and showed up at the house.

“But again, that’s unconfirmed and what we’re working on right now.”

Ms Chapman’s family have paid tribute to her, telling Delaware Onlineshe was a “beacon of light to anyone who was fortunate enough to meet her”.

“She loved her family fiercely, was a compassionate friend and among the most talented and innovative professionals in her field,” the family statement read.

“Her death was sudden and tragic, but will not define who she was to the thousands of people who loved her. Her family is devastated, heartbroken and requests privacy and respect as they grieve.”