OMAHA, NE — Leonna Dalton-Phillip's future was as bright as her smile. A straight-A student at an Omaha high school and co-captain of its drill team, the 18-year-old was full of happiness and promise on Christmas day, talking with her father, Claude Phillip, about which of several college scholarships to accept. California perhaps? They'd have plenty of time to decide, they figured.

Phillip, who lives in Des Moines, kissed his daughter on the forehead and told her he loved her when he dropped her off at her grandparents' home later that day. She said she loved him, too, and gave him an embrace that lasted about a minute. Now, the loving hug will have to last a lifetime. Dalton-Phillip and her grandparents, John Dalton, 70, and Jean Dalton, 65, were shot to death in the Daltons' Omaha home Tuesday evening. The gunman, Omaha police said, was their son, John W. Dalton Jr., 46, who spent 11 years in prison for killing his wife before he was paroled in 2010.

The suspect was arrested Wednesday in Tennessee after a manhunt. Police haven't disclosed a motive. Claude Phillip told ABC News that he hasn't seen the suspect in years, but his daughter was suspicious of her uncle.

"She just kinda felt he wasn't right and she had the right feeling because she is gone by his hands. He did this and it hurts," Phillip said. "I'm devastated. … I don't know how I'm going to go on." Whatever provoked the attack happened quickly. Police have said Dalton-Phillip's car was still running outside her grandparents' home when they arrived. She had gone there to pick up her little sister, London, who is about 6 or 7, KETV reported. The little girl hid as her family was gunned down, then ran to a neighbor's house about 7:30 p.m. and said, "They shot my family," the Omaha World-Herald reported.

By all accounts, the Daltons were lovely people whose kindness was measured by the way they treated strangers. Phillip told the World-Herald that even though he is no longer with the girls' mother, Jalisa Dalton, he's still treated like family and his other children are treated like grandchildren.

Leonna Dalton-Phillip lived with her mother, who Phillip said was "just in shock."

"We all are," he told the World Herald. "I can't believe this is happened." Phillip said the world lost a luminary in his daughter, a strikingly beautiful young woman. "She was so smart and bright," he told the World Herald. "Last April or May, she won an essay contest on the Holocaust. There were 300 entries, and hers was the best one."