A Riverside County jury on Tuesday convicted Jason Hann of first-degree murder and assault on a child resulting in death.
Prosecutors say the 38-year-old Vermont man hit his daughter, Montana, to stop her from crying in Desert Hot Springs in 2000. Authorities say Hann and the baby's mother put the body in a plastic container and moved away. Her decomposed remains were found in 2002.
Hann already is serving 27 to 30 years for the 1999 murder of his 6-week-old son in Vermont. That killing makes him eligible for the death penalty in the current trial.
Krissy Werntz of Indiana also is charged with murder.