COLORADO SPRINGS, Colo. -- A father who lost his children in a house fire was convicted Tuesday of murder and arson in their deaths.

Timothy Nicholls showed no emotion as the judge read the verdict. He had been charged with 19 counts, including first-degree murder, arson, drug possession, child abuse, animal abuse, conspiracy and theft.

Jurors couldn't reach a decision on charges of conspiracy to commit first-degree murder and premeditated first-degree murder, but his conviction on a first-degree felony murder charge means Nicholls will serve life in prison without the possibility of parole.

Sentencing was set for May 17.

A fire on March 7, 2003, destroyed the Nicholls family's home and killed his children, Sophia, 5, and Sierra, 3, and his wife's son, Jay, 11. Nicholls was injured.

Arson investigators later found traces of an accelerant on the children's pajamas, and a mostly empty can of highly flammable cleaning solvent was found under bushes outside the home.

Nicholls' wife, Deborah Nicholls, was not home when the fire broke out. She faces trial in August on charges of methamphetamine possession and felony theft on accusations she tried to make a false insurance claim for a car undamaged in the fire.

The couple has since divorced.

Prosecutors alleged Nicholls set the fire to collect insurance money. Defense attorney Dennis Hartley had argued the fire was accidentally caused by a candle.

In testimony during trial, Nicholls denied setting the fire or planning to kill his children, whom he said he loved.

Jan Miles, a friend of the Nicholls', said she believed Nicholls was wrongfully convicted.

"I watched him play with his children," she said. "These people loved their children."