Virginia Dad Allegedly Holds Gun to Son's Head in Pic, Threatened to Kill Him

A Virginia man is facing multiple charges after he allegedly held a gun to his young child's head and threatened to end his life -- and we have the horrifying photo.

Matthew Williams -- who is a convicted felon -- was arrested on April 21 by Richmond police after they were made aware of the incident. He was subsequently charged with attempted murder in the first degree, child abuse, use of a firearm in the commission of a felony, and possession of a weapon by a convicted felon, according to court documents obtained by TMZ.

Police say they responded to a home on Ingram Avenue April 20 after the minor's mother called in to report the incident ... claiming she was on FaceTime with 25-year-old Williams and their son when he pointed a firearm at his head and threatened to kill her and the young boy.

The photo shows it all -- the boy appears petrified as he grabs the barrel of the silver semi-automatic handgun that's pushed against his head.

Williams -- dressed in just boxers and socks -- allegedly "refused to comply" with police demands at the scene, but he was eventually detained.

Officers obtained a search warrant of the home ... and they found several weapons, including a Taurus 1911 Commander semiautomatic pistol, a Micro Draco pistol, a Stevens breech-loading rifle, a Pachmayr breech-loading shotgun, a F.lli Pietta revolver, and miscellaneous ammunition.

Williams is being held without bail and has a jury trial date set for August 25. He's been previously convicted of felony burglary and misdemeanor vehicle tampering.