SAN ANTONIO -

A violent argument ended when a father pulled a knife and stabbed his son, police say.

The argument and stabbing happened at a house in the 400 block of San Blas around 2:30 Saturday morning,

Investigators say the father and son argued over property the son had pawned.

They say the father pulled a knife and stabbed the son in the lower back.

EMS transported the son to University Hospital in critical condition.

Police arrested the father on the scene and say he now faces charges of assault with a deadly weapon.