Chiefs' Eric Bieniemy's Son Arrested For Allegedly Shooting His Mom

Jaw-dropping development in the shooting of Eric Bieniemy's wife, Mia ... the couple's 27-year-old son, Elijah, has been arrested for the horrific act.

Elijah Zion Bieniemy is currently behind bars and being held without bail at a Virginia jail after allegedly opening fire on his own mother, hitting her multiple times, inside the family’s Ashburn home Sunday evening.

Bieniemy -- who posed for a mugshot after his arrest -- was charged with Malicious Wounding, Use of a Firearm in Commission of a Felony, and Discharge of a Firearm Inside of a Dwelling, according to a rep for the Loudoun County Sheriff's Office.

It's unclear what led up to the shooting.

Elijah is one of Eric and Mia's two children.

Eric was halfway across the country when the nightmare unfolded ... the K.C. Chiefs offensive coordinator was in Missouri, preparing for training camp.

The Chiefs released a brief statement after news of the violent incident became public, saying, “The club is aware of the incident involving Eric Bieniemy’s family. Out of respect for their privacy, we won’t have a comment at this time. Our thoughts and prayers are with them.”