Police have offered no motive for why Kreider, a seemingly typical youth who had worked at McDonald's and just completed his sophomore year at Manheim Township High School, killed Thomas Haines, 50; his wife, Lisa, 47; and their son, Kevin, 16, a friend of Kreider's since elementary school.
"I can't believe that he did that," Alexa Priester, 16, who rode the school bus with Kreider, said yesterday.
The Monday after the killings, Priester said, Kreider was crying on the bus. She tried to console him.
"I told him, 'I know you're friends with Kevin. I'm really sorry. If you ever need anyone to talk to, I'm here for you.' "
Classmates said Kreider and Haines were good friends who shared an interest in military history, particularly World War II. The two could often be found afternoons at Caruso's Pizzeria, a hangout next to the high school, said Vita Caruso, daughter of the owner, who knew both boys.
Kreider "seemed really normal," Priester said. He "was a very funny, nice person. He was very, very smart and really enjoyed talking to you about politics, really serious topics."
He and his brother, who is three years younger, "were always joking around on the bus," she said. "They were always happy."
Kreider has a sister who graduated from high school last year, Priester said.
Friends said Kreider took advanced classes and possessed a dark sense of humor. He enjoyed martial arts and often joked about beating people up. But they could not begin to imagine why he would want to hurt Haines.
Kreider split his time between the homes of his parents, Timothy and Angela, who are divorced. Lexi Colombo lives across the street from Angela Kreider and attended the Haineses' memorial service at Otterbein United Methodist Church on May 19. Alec Kreider was there, with his family, in tears, she said.
"He seemed really upset. To find out he did it doesn't make sense," said Colombo, 16.
She recalled that Kreider gave a friend of hers a bouquet on the last day of class. But, she said, "there always seemed to be two sides to him. Now, after the fact, it could have been him, but I don't want to believe it."
According to the police affidavit, Kreider told his father that he entered the Haineses' Peach Lane home intending to smother Kevin. Police would not say how the crime escalated to involve three people or whether they had recovered the knife used in the slayings.
The Haineses' daughter, Maggie, 20, who was in the house, heard a disturbance around 2:20 a.m. She went into her parents' room, where her mother told her to get help, police said. She ran to a neighbor's house and called 911.
When police arrived a few minutes later, the three Haineses were dead.
District Attorney Don Totaro has said Kreider acted alone. Police have not said in what order the family members were attacked and have not described the elder Haineses' conditions when their daughter entered their bedroom. Thomas Haines was lying on the bed and Lisa Haines was sitting on the edge of the mattress.
Totaro did not return calls for an interview yesterday.
One of the biggest questions in the case is how one slightly built teenager could wreak such havoc.
Autopsy reports show that Thomas Haines, a businessman and competitive runner, was stabbed in the chest. Lisa Haines, a preschool teacher, was stabbed in the abdomen, and Kevin Haines was found in a second-floor hallway with wounds to the neck and chest.
The intruder apparently entered through an open back door.
After the family was killed, Kreider allegedly went to his mother's home on Cobblestone Lane, but police did not say whether she was home at the time. Kreider's father lives nearby on Dolly Drive.
Alec Kreider was charged as an adult and was held without bail in Lancaster County Prison. He was charged with three counts of homicide and one of burglary, and could receive life in prison. He is ineligible for the death penalty because he was a juvenile when he allegedly committed the crimes.
The killings shook residents of the Blossom Hill neighborhood, many of whom stepped up security out of fear that the killer had picked the Haineses' secluded two-story Colonial at random.
Kevin Haines was a dedicated Boy Scout and active in his school's quiz bowl and on the student newspaper. He was looking forward to a trip to Germany this summer with classmates.
Robert Beyer, a lawyer acting as a spokesman for the Kreider family, said they had nothing to say about their son and hoped people would respect their privacy. Kreider's attorney, Jack Kenneff, declined to discuss the case.
The Manheim Township School District said in a statement that counselors were on hand to talk to summer-school students.
Contact staff writer Kathy Boccella at firstname.lastname@example.org or 610-313-8123.
Staff writer Jeremy Rogoff contributed to this article.