A father accused of intentionally plowing into several cars at 75 miles per hour with his 2-and-a-half-year-old son left unbuckled in the car has pleaded not guilty by reason of insanity.

Nathan Weitzel appeared in Arapahoe County court Thursday morning. He has been charged with attempted first-degree murder, child abuse, assault, criminal mischief, possession of a controlled substance and vehicular assault for the Aug. 21 incident, which left his son Isaiah in a cast over half his body.

At the time, Weitzel told Arapahoe County investigators “the reason he wanted to kill Isaiah was because being a father was a big responsibility and he did not think he was man enough to raise a child.”

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He also told investigators “I was trying to kill my son” and used cocaine that day, court records say.

Isaiah was taken to Children’s Hospital Colorado, where he was treated and went home after several days.

The boy’s mother said she takes care of Isaiah full-time, but that he spent weekends with his dad. He was supposed to be brought back to his mom the afternoon before the crash.