Shaking and holding his head in his hands, a man who admitted killing his girlfriend’s 3-year-old daughter told a courtroom Friday that he wasn’t worthy of forgiveness.

“I accept full responsibility in the death of Sydni Perkins,” Jason W. Dillon said during his sentencing in Douglas County District Court. “I don’t know what caused me to do what I did.”

Dillon, 23, said he couldn’t look at himself in the mirror “knowing I murdered the girl I called my daughter.”

He said he regretted doing cocaine and drinking alcohol in the hours before Sydni’s death on June 18, 2005, but that blaming the drugs would be too easy.

At the end of the roughly half-hour hearing, District Court Judge Michael Malone sentenced Dillon to 199 months – roughly 16 1/2 years – in prison for second-degree murder and child abuse.

“You took the most precious person from me,” Sydni Perkins’ mother, Rachel Perkins, told Dillon during the hearing. “I walk around in a fog, feeling incomplete. … There is no pain like the pain of a mother losing her baby.”

Rachel Perkins’ mother, Tracey, said she wished Dillon would suffer every day while in prison.

“Sydni is an angel. She’s up in heaven, and she’s watching down on us,” she said.

Dillon initially was charged with first-degree murder but entered a plea earlier this year, a deal that prosecutors said was endorsed by Sydni Perkins’ family to spare them the pain of going through a trial.

Dillon, who lived with Rachel and Sydni Perkins in the 1100 block of George Court in northern Lawrence, was baby-sitting Sydni the day of her death after being out all night at a friend’s birthday party in Kansas City. When Rachel Perkins got home from work about 5 p.m., she found her child alive but unresponsive, and Dillon told her she had fallen in the bath.

Eventually, Dillon admitted to police that during the day he knocked Sydni to the ground, shook her when she refused to help him pick up laundry and finally struck her in the back of the head with his hand 13 or 14 times after she told him she didn’t want him to be her daddy anymore.

“He did not want or mean to kill her,” said Darin Mangan, a friend of Dillon’s who spoke on his behalf at sentencing.

Mangan told the judge he met Dillon in 1997 while taking a college course that required him to work with at-risk youths. Dillon grew up in Eudora, lived in state custody in a boys’ group home while attending Lawrence High School, and then went to Kansas City, Kan., Community College.

“Jason beat the odds of what was expected of him,” Mangan said.