She was likely killed early Monday morning, authorities said.
"She should be remembered for being more than just a star softball player, because she was way more than that," said Brooke Keenan, 22, a captain on the Rutgers team. "She was a great person."
Stephen Headley, 28, a Florence resident, was charged Tuesday with murder in connection with Ayres' death. Police and prosecutors would not say how they tied Headley to the crime.
The Rutgers team held a meeting Tuesday after learning about Ayres' death from their athletic director.
"All of us and the coach sat there for an hour crying with each other," said Kate Sharples, a teammate. "No one really said anything. No one really knew what to say."
Ayres' family reported her missing to the Deptford Township police early Monday afternoon, said Deptford Detective Sgt. George Johnson.
She and Headley knew each other, but authorities didn't offer more details on how they knew each other and how well.
Headley's bail is set at $750,000.
On Monday evening, Headley asked his grandmother, a Medford resident, to drive him to his mother's house in Pemberton because he wanted to meet with the two of them, the Prosecutor's Office said.
During the meeting, he ran out of the Pemberton house into the street and was hit by a pickup truck. He was airlifted to Helene Fuld Medical Center in Trenton, where he is being treated for a fractured back, two fractured ankles, and multiple fractured ribs, authorities said.
The investigation also involved the Prosecutor's Office and the police departments of Medford, Pemberton, Florence, and Deptford Townships.
At Deptford High, Ayres recorded a school record 920 strikeouts, according to the high school. She later attended Fordham University on an athletic scholarship.
"This is a shocking and terrible loss," the Rev. Joseph M. McShane, president of Fordham, said Tuesday in a statement. "I cannot imagine the grief Nicole's family must be feeling today, a grief intensified by the death of someone so young."
In 2007, she was named the Atlantic 10 Conference's Rookie of the Year, according to the school. When she made the A-10 All-Conference team that year, she had the second-most wins ever by a Fordham freshman with a 16-4 record. She finished with a 2.03 earned-run average and 133 strikeouts.
"We are absolutely stunned to hear about Nicole. It's a sad day for us and the players who knew her. Our prayers and thoughts go out to her family and friends in this extremely difficult time," Fordham softball head coach Bridget Orchard, who coached Ayres in the 2007-08 season, said in a statement.
She left Fordham after her sophomore year.
She took classes at Rutgers in the 2009-10 school year, but was not enrolled as a full-time student, said a university spokesman.
Ayres, who was expected to play on the Rutgers team in the spring, bonded with her future teammates when they played in a women's fast-pitch summer league.
"From here on, we're going to win everything for her," Keenan said. "We are just going to take it all the way in her memory."
Teammates said Ayres had a long-term boyfriend. She was a jokester and they could count on her on the mound. They called her Nicky or by her number: 5
During a summer-league game, she threw seven shutout innings and kept striking hitters out.
"That was her night," Sharples said.
Contact staff writer Darran Simon at 856-779-3829 or firstname.lastname@example.org.
Inquirer staff writer Jan Hefler contributed to this article.