Woman kills husband's mistress then turns gun on herself in calculated attack: Police

A Delaware woman broke into the Pennsylvania home of her husband's mistress and shot her in the head before turning the gun on herself, according to police.

The suspect, 47-year-old Jennair Gerardot of Wilmington, knew about her husband's affair with 33-year-old Meredith Chapman and carried out a "calculated, planned attack" to kill Chapman, Radnor Township Police said at a news conference.

Both Chapman and Jennair Gerardot's husband had recently worked at the University of Delaware.

On Monday Jennair Gerardot broke into Chapman's house in Radnor Township, a Philadelphia suburb, where she waited for Chapman to come home, police said.

As soon as Chapman walked in the door, Jennair Gerardot shot her in the head, police said.

Jennair Gerardot then turned the gun on herself, shooting herself in the head, according to police.

Both women were found dead inside Chapman's Radnor Township home, an area police described as a tight-knit community.

Jennair Gerardot's husband, Mark Gerardot, was in the driveway when officers arrived. He told them, "My wife may be inside," police said.

Police said they believe Mark Gerardot was in the area because he had planned to meet Chapman for dinner, and when she didn't arrive, he became concerned and went to her house.

Police said emails and texts indicated Jennair Gerardot's attack was pre-meditated. Police also noted that it appears Jennair Gerardot brought a bag containing a wig and clothing with her. Jennair Gerardot didn't drive to Chapman's home and it wasn't immediately clear how she got there, police said.

Mark Gerardot worked for the University of Delaware from November 2017 to April 2018 and he left the university earlier this month, University of Delaware spokeswoman Andrea Boyle Tippett said.

Chapman worked at the University of Delaware from 2010 to March 2018, Tippett said. She also received her bachelor's degree from the University of Delaware in 2007 and her master's from the university in 2015.

"Everyone who knew and worked with Meredith is heartbroken," Tippett told ABC News via email. "As a proud alumna of UD, her commitment to her work was exceeded only by her boundless energy. She believed earnestly in the power of communication to bring people together, whether to achieve their collective goals or simply to share their stories. We will miss her."

Chapman also worked as an assistant vice president of marketing and creative services at Villanova University and ran for the state senate in Delaware in 2016.

A former student remembered Chapman as a mentor and role model for her, while she was a student at the University of Delaware.

"She was a vibrant and engaging teacher who went out of her way to help grow the communications careers of students at the university -- young women in particular," the student told ABC News via email. "She was instrumental in creating a community of successful and aspiring communications professionals through her classes and the award-winning UD Social Media Ambassador program she helped to create.

"During her 2016 run for district senate a group of students, including myself, helped to support her campaign and she let us know that working with her UD students motivated her to be a better professor and advocate for a stronger education system and job opportunities for the next generation," the student said. "Even though she lost the election, Professor Chapman accepted her loss with grace and utilized it as a teaching moment to inspire us all to take risks and pursue our passions no matter the odds."