Published: Mar 06, 2013 11:39 AM EST
Updated: Mar 06, 2013 5:07 PM EST

LEE COUNTY, Fla.- Jurors in the murder trial against Ryan Costello have found him guilty on all charges. Those charges include manslaughter, neglect of a child and tampering with evidence.

Prosecutors said the Lee County father was responsible for the death of his 11-week-old son, Darwin. The defense said allegations that Costello beat his son to death are purely circumstantial, and that he should be found not guilty.

Costello beat his son Darwin to death after getting into a verbal and physical altercation with the child's mother, Whitney. The child died in 2010 after being brought to Healthpark Hospital in Fort Myers.

When police went to the Costello's South Fort Myers home to investigate, they found a room that was later described as a marijuana grow room. They also found numerous bottles of oxycodone.

Whitney Simonsen, the child's mother was arrested on drug charges. She accepted a plea deal to spend 10 years on probation in return for her testimony against her.