ANDOVER — The young teacher was as comforting as she was clever, often reaching out to her students with a soothing smile and math jokes.
At 24, Colleen Ritzer had become a role model for many of her students at Danvers High School, where they had come to know her as smart, gracious, and persistent, as diligent about grading their geometry problem sets as helping to ground them amid the turbulence of adolescence.
In her second year of teaching at Danvers, she also connected with them through social media, especially on Twitter, where she offered answers to algebra problems and a steady dose of wisdom.
“No matter what happens in life, be good to people,” Ritzer tweeted this summer on an account that describes her as a “math teacher often too excited about the topics I’m teaching.” She also said, “Being good to people is a wonderful legacy to leave behind.”
It’s a legacy for which she will be remembered, said many of her students, friends, and others after police found her body early Wednesday in the woods behind the high school.
A 14-year-old student, Philip Chism, is being held in connection with the slaying.
Sophomore McKenzie Plaza described the raven-haired teacher as “lighthearted, kind, and genuinely nice.”
“She was always smiling, and she really loved what she did and loved working with us,” said Plaza, who had Ritzer as a homeroom teacher.
“She gave off the impression that you could talk to her about anything. You just enjoyed her presence.”
She recalled how Ritzer loved pink and often wore jewelry adorned with turtles.
“Her presence was really comforting, and now she’s not there anymore,” Plaza said.
“It’s just really sad, freaky, and scary. It doesn’t seem real yet.”
Ritzer lived with her parents in Andover, where she grew up, the oldest of three children.
In a statement, her parents, brother, and sister asked for privacy as they mourned the death of “our amazing daughter and sister.”
“Everyone that knew and loved Colleen knew of her passion, her teaching, and how she mentored each and every one of her students,” they said.
In a separate statement, officials at Danvers Public Schools said they lost “a dynamic and brilliant ray of light.”
“Colleen Ritzer was everything one could ask for in a teacher — dedicated, passionate, and invested in her students,” they said. “Our entire community will feel this loss for many years to come.”
Before she became a teacher, Ritzer stood out as a stellar student at Assumption College in Worcester, where she majored in mathematics, minored in psychology, and graduated two years ago magna cum laude.
“The Assumption community will keep Colleen’s family members in its thoughts and prayers during this time of great sorrow,” Assumption’s president, Francesco Cesareo, said in a statement.
Ritzer was also pursuing a master’s degree in school counseling at Salem State University.
“Colleen was a bright and vibrant student,” Patricia Maguire Meservey, the president of Salem State, said in a statement.
“As a dedicated teacher, Colleen wanted to work with and help children with special needs. She believed children have much to offer and often do not realize how special they are.”
Ritzer was precocious and clear about wanting to be a math teacher well before she graduated from Andover High School in 2007.
In her yearbook, she wrote: “Being grown up isn’t half as fun as growing up.”
Mary Duffy, who has lived next to the Ritzers since the family moved there decades ago, said she was surprised when, as a high school student, the young woman told her she wanted to teach mathematics.
“That’s not something you hear very often from someone her age,” she said. “But she was very good at it.”
She called her death “heartbreaking and devastating.”
“If every family was like the Ritzers, none of this would happen anywhere,” she said.
“I really can’t think of a more wholesome family. They’re wonderful.”
One of Ritzer’s oldest friends, Jennifer Berger, described Ritzer as a diligent baker, fan of country music and hockey, lover of Christmas and cruises, and an aspiring mom searching for the right guy.
Berger last saw her friend since kindergarten over the weekend, when they went shopping for Halloween greeting cards.
“She wanted to send them to her old college roommates to wish them Happy Halloween,” she said.
“Who does that? Colleen does.”
As they baked Reese’s Pieces cookies on Saturday night at Berger’s home in Andover, Ritzer discussed her students.
“She was telling me that she was having a good year,” she said. “She loved all her classes.”
And on her Facebook page, Ritzer recently posted a quote from Ralph Waldo Emerson:
“To know even one life has breathed easier because you have lived, this is to have succeeded.”
On her Twitter page, decorated with pictures from a recent pumpkin-picking excursion, there are tweets about making her first-ever apple crisp, birthday wishes she sent to students, and reminders to change clocks when Daylight Saving Time ended.
After the Boston Marathon bombings in April, she quoted Mr. Rogers, saying:
“I would see scary things in the news, my mother would say, ‘Look for the helpers. You will always find people who are helping.’ ”
She added: “This world is a crazy place. Love who you love and live every day.”
On Sept. 11, she wrote that she was “always thinking of the innocent victims . . . and the loved ones left behind who live in their light every day.”
In a more recent tweet, which she sent this month, Ritzer reminded her students they should always look for the good in things by citing this quotation:
“Every day may not be good, but there is something good in every day.”Globe correspondent
Melissa Hanson contributed
to this report. David Abel can be reached at email@example.com. Kathy McCabe can be reached at firstname.lastname@example.org.