Published: Jun 15, 2010 11:06 PM EDT
Updated: Jun 15, 2010 8:07 PM EDT

Fort Myers, Fla -  WINK News continues to uncover new details in a heart-breaking child abuse case.

Four-month-old Darwin Costello is brain dead after being beaten this past weekend at his Fort Myers home.

In a detailed sheriff's report we got our hands on Tuesday, the baby's father, Ryan Costello admits to hurting his own son.

The report state, 31 year-old Ryan Costello confesses to nearly beating his baby to death saying, "I killed my kid".

Darwin Costello clings to life following the vicious beating Sunday at his home on Portofino Springs Blvd in Fort Myers.

In addition to say he "killed his kid", Ryan Costello describes himself as a "murderer".

His son Darwin is still alive.

However, the report says he newborn is brain dead and being kept alive by a respirator.

His injuries include multiple skull fractures, internal bleeding, signs of strangulation, broken bones and massive head trauma.

Neighbors told WINK News they had no idea what was going on in the plush townhouse.

In addition the vicious beating, detectives say the home was also a growhouse.

Multiple marijuana plants were found as well as cocaine and prescription drugs.

24 year-old Whitney Simonsen, Darwin's mother and Ryan's girlfriend was arrested Sunday after the drugs were found in her home.

She is not charged with the beating.

She bailed out of jail Monday afternoon, but was re-arrested Monday night on drug trafficking charges.

The Department of Children and Families took the couple's other child, a two year old boy and placed him in foster care.

Ryan Costello is being held without bail.

Whitney Simonsen's new bail hasn't been set.