SEMINOLE COUNTY, Fla. -- Just three weeks after a Seminole County man was sentenced to life in prison for murdering his girlfriend's 2-year-old son, Jason Lenz is already planning an appeal.

Lenz's attorney told Eyewitness News some major mistakes were made in his first trial.

The trial seemed to wear on Lenz. He broke down repeatedly in the days before a jury convicted him of first degree murder in the death of A.J. Cabral. His first trial ended in a hung jury.

“The reason we're appealing this case is obvious. He's sentenced to life in prison,” attorney Richard Hornsby said.

Yet Wednesday, Lenz's attorney told Eyewitness News he's pushing for yet another trial for his client. He says a series of decisions by Judge Debra Nelson left Lenz tainted in the eyes of his jury.

“If I was a betting person, I'd put my odds on this case being reversed on appeal,” Hornsby said.

Lenz was babysitting Cabral, his girlfriend's son, on the January 2009 night that the boy died of blunt for trauma. Lenz claimed to be close with the young boy, but Judge Nelson excluded most background testimony about their relationship.

When the child's mother testified, without being asked, that Lenz once punched a hole in the wall in a fit of anger, Hornsby said jurors had no context.

“The jury was left with the picture of a violent person who didn't have any relationship with this child, when in fact that was the complete opposite,” Hornsby said.

Prosecutors argued that Lenz slammed Cabral into the bedroom wall, even though Lenz said he only tripped while carrying the boy.

Hornsby says an accidental fall is closest to the charge of "aggravated manslaughter," a charge the judge never asked the jury to consider as its own verdict.

Defense attorneys face a Monday deadline to file their case in the 5th Circuit Court of Appeals in Volusia County. The State Attorney's Office does not comment on pending cases.