By Matt Goodman,

Rashad Davis, 32, was fired from the Dallas Police Department following an internal investigation on Jan. 3, 2011. (Credit: DPD)

DALLAS (CBSDFW.COM) – An officer facing multiple charges for assaulting his girlfriend and who later tested positive for using marijuana has been fired following an internal investigation, a police department spokesman said Tuesday.

Officer Rashad Davis, 32, was arrested Dec. 6 on an Assault (Family Violence) charge for attacking his live-in girlfriend. She alleged he grabbed her by the throat and threw her onto a bed. Davis was placed on administrative leave after he was released from jail.

While on leave, a police report says Davis attacked his girlfriend once more, throwing her to the cement ground outside their apartment. This resulted in a second Class A Misdemeanor Assault (Family Violence) charge.

According to police, as their investigation progressed, Davis’s girlfriend said he pointed a gun at her head in November. Police then filed a third charge of Aggravated Assault (Family Violence) and issued a warrant for his arrest.

Police raided Davis’s apartment on Dec. 13, but he was not home. He turned himself in on Dec. 16 without incident, the department reported on its Facebook page.

On Dec. 8, after being arrested the first time and placed on leave, police had Davis take a drug test. Results came back on Dec. 13 and showed that Davis tested positive for using marijuana, a department statement said.

According to a release issued Tuesday, Davis had also violated the conditions of the department’s Administrative Leave Policy and was insubordinate after he refused to cooperate in the internal investigation.

Davis, a four-year veteran of the force, was assigned to the South Central Patrol Division. He has the right to appeal the firing, the release notes.