Professor Vibeke Rasmussen always showed up for her teaching job at Quincy College in Plymouth, where she joined the adjunct faculty seven years ago. When she didn’t report for class Friday morning, the school called Rasmussen’s daughter, who reported her mother’s absence to Plymouth police.

Officers arrived at Rasmussen’s apartment on Tideview Path around 1 p.m., where they found the door unlocked. Inside, the 76-year-old Rasmussen was dead, having suffered 35 stab wounds to her face, neck, and shoulders, an official said.

“This was an incredibly vicious attack,” Plymouth District “This was an incredibly vicious attack,” Plymouth District Attorney Timothy J. Cruz said Saturday during an interview at the Plymouth police station. “It was just a very heinous, a very gruesome act.”

The discovery sparked a manhunt for Rasmussen’s 24-year-old neighbor, Tyler Hagmaier, who has a history of mental illness and “criminal occurrences with the police,” Cruz said.

Police issued a bulletin for him and his silver Prius Friday and contacted his family in Western Massachusetts, the district attorney said.

Around 10 p.m. Friday, officers found Hagmaier’s vehicle, but no sign of him, Cruz said. His Prius had been abandoned on the French King Bridge, which spans the Connecticut River in Gill, a town of about 1,500 people in the northwest corner of the state, Cruz said.
Witnesses told investigators that they heard a splash around the same time police found the Prius, but searches of the river on Friday and Saturday did not turn up Hagmaier, the district attorney said.

“We believe that he may have jumped, but as of right now . . . we do not know if that’s true,” Cruz said. “There’s been no body that’s been recovered.”

The search of the river is expected to resume Sunday and Cruz said the public should not approach Hagmaier if they encounter him.

Hagmaier has a history of threatening to commit suicide, prompting calls to police for help, Plymouth Police Chief Michael E. Botieri said. In the past year, Botieri said officers fired a bean-bag round at him to disarm Hagmaier of a knife that he intended to use to hurt himself.

“We’ve never arrested or charged him with anything,” he said.

Cruz said Hagmaier and Rasmussen had only been neighbors for a few weeks.

Hagmaier worked nearby at Mirbeau Inn & Spa at The Pinehills until late last year, according to a spokeswoman for the spa.

Investigators believe Rasmussen was killed Thursday night. Cruz said she arrived home around 9 p.m. and neighbors told police they heard a woman screaming from Rasmussen’s apartment around 11 p.m.

He said police have not identified a motive in the killing of Rasmussen, who was described by Quincy College as a “gifted instructor” on the school’s Plymouth campus.

One of her students, Heather Lynch, 25, said she was scheduled to attend Rasmussen’s biology class Saturday morning. She said another student informed her of Rasmussen’s death.

“She was very much into bringing real life into what we were learning,” said Lynch, who lives in Plymouth. “She was so personable. Going to class wasn’t boring.”

Rasmussen was interested in nutrition, advising her students to stick to the perimeter of the supermarket when they went grocery shopping, Lynch said. The center aisles, Rasmussen warned, were where stores displayed their most unhealthy products, Lynch said.

She also told students that she got her salt from the ocean, not a store, by collecting seawater and letting it evaporate, Lynch said.

“She was so vibrant,” she said.

Lynch said she last saw Rasmussen in class on April 30, when Rasmussen led a lab in which students extracted DNA from strawberries and helped prepare the class for final exams, she said.

Three police cruisers were stationed in Rasmussen’s apartment complex and an officer stood in the doorway to the building where she lived across from Hagmaier.

Jennifer Galvin, 37, who lives nearby, said the complex is a close-knit community. “She wouldn’t have put up a fight. This woman, she would let someone come into her house and take anything,” she said. “I have no words.”