Texarkana Texas Police say they are investigating the city's 2nd homicide of 2012.Authorities say that charges have been upgraded from aggravated assault to murder following the death of 43 year old Michael Johnson. Johnson and 22 year old Brian Tremayne Porter became involved in an altercation, which police say led to Porter allegedly hitting Johnson on the side of his head with his fist.

Johnson's body has been sent to Dallas for an autopsy and Porter is jailed at the Bi-State Justice Center in Texarkana on murder charges.