Further ballistics tests have raised questions about who may have pulled the trigger in the Dec. 22 shootings.
Sources inside the Dallas Police Department told NBC 5's Grant Stinchfield that they could not get an exact match from bullets fired from former Utah state trooper Brian Smith's gun and those used in the freeway shootings.
One high-ranking investigator said it is very hard to match bullets fired from a Glock. They still believe the state trooper is the shooter but the latest round of testing has not been able to confirm that.
During a news conference on Monday afternoon, Lt. Craig Miller said the department was still confident that Smith did the shooting in the Dallas incidents on Dec. 22. Police said they are still waiting on final ballistic test assessments from the Dallas County medical examiner's office and that no further formal announcement on the case will be made until all testing is complete.
Police said Smith resigned from his position as a Utah trooper in May, had an addiction to pain killers and was wanted in connection with a North Texas crime spree.
The crime spree appears to have begun in Garland, where a man police identified as Smith jumped over a pharmacy counter and stole Oxycontin pills.
Smith died from a self-inflicted gunshot wound following a standoff in Garland the night of the shootings.
