Santa Ana man pleads not guilty to beating infant son

Jonathan Reyes ( Santa Ana Police Department )

A Southern California man has pleaded not guilty to badly beating his 2-week-old son, who also had methamphetamine in his system.

Jonathan Reyes of Santa Ana entered pleas Wednesday to child abuse charges.

Related: Man arrested for child abuse of 13-day-old infant in Santa Ana, police say

Prosecutors say Reyes was out on bail in a robbery case when he attacked his son Monday while his girlfriend was taking a nap. Police say the woman awoke to find the child badly injured.

The child had a fractured skull and internal injuries and tested positive for methamphetamine.

Police say they believe the meth came from contact with Reyes, who allegedly acknowledged using the drug.