TWINSBURG, Ohio -- Twinsburg police are continuing their investigation into the shooting death of Officer Joshua Miktarian.

Prosecutors said they recovered a 9 mm handgun, believed to be the murder weapon, from a Bedford Heights home where suspect Ashford Thompson was arrested.

Thompson is charged with aggravated murder in connection with the Twinsburg police officer's death.

Investigators also said they found bullets Monday evening during a search of the crime scene. They also searched for evidence inside Thompson's mother's home, which is located near the shooting scene.

Thompson's clothing and hands have also been tested for gunpowder residue, and results of these tests are pending.

Twinsburg prosecutor Dave Maistros also said charges are possible against Thompson's girlfriend or family members if it is discovered that they helped him after the shooting.

Police said Miktarian stopped Thompson early Sunday morning because he heard loud music and suspected him of drunken driving.

Investigators said Thompson shot Miktarian in the head four times.

Thompson has a short criminal record, including traffic tickets, a drunken driving offense and driving with illegally tinted windows.

Thompson is a LPN who worked independently as a home health care worker for three people on Medicaid.