The Delaware woman who killed herself after gunning down a Villanova University official she believed to be having an affair with her husband may have spied on her target in the days before the bloody attack, police say.

Jennair Gerardot, 47, shot and killed her husband’s mistress, 33-year-old Meredith Chapman, inside Chapman's home in Radnor Township on April 23. But one of Chapman’s neighbors told police she spotted a woman near her driveway with “a grim, concerned or worried look” and clutching a pair of binoculars just two days before the murder.

The neighbor wrote she “thought she might have lost a pet,” but she said she witnessed the woman staring intensely in the direction of Chapman’s home, Radnor Township Police Superintendent William Colarulo told Philly.com.

“In light of the tragic incident that occurred on Lowry’s last night,” the email read, “I feel compelled to tell you about something I observed on Saturday.”

Gerardot blasted a single shot through Chapman’s head that Monday as she walked into her house upon returning from work. Gerardot then turned the gun on herself. Police later ended up finding a pair of binoculars in the rented vehicle Gerardot used to drive from Wilmington on the day of the shooting.

“Could the results have changed? We’ll never know,” Colarulo said when asked if the tip could have been used to prevent Chapman’s death. He told Philly.com officers would have at least visited Chapman and questioned her.

The neighbor, meanwhile, reportedly said she did not initially alert police because the entire episode was brief and it didn’t seem like a criminal act.

Chapman, an assistant vice president at Villanova University, previously worked with Gerardot’s husband, Mark, at the University of Delaware. Mark Gerardot, at police headquarters, had stated after the shooting that there was a “domestic issue” all three were dealing with, officials said.

Prior to her death, Chapman had divorced former Newark City Councilman Luke Chapman, according to Philly.com. Jennair Gerardot, in increasingly desperate posts made to a neighborhood discussion app starting in February, said she was seeking a marriage counselor because her husband was “telling me he wants a divorce.”