The 6-year-old girl, who was steps from her Georgetown home, was able to break free.
The force would grow to 4,000 officers in four years under Muriel E. Bowser’s plan.
A suspected gunman was seen running away after the incident in an apartment complex in Northwest D.C.
The suspect had the gun in a bag that was within reach of a child in the vehicle’s back seat, police said.
A man was fatally shot over the weekend in the area, which has seen numerous violent incidents in the past few months.
A recent bust in the D.C. area was described by officials as one of the largest in recent memory.
Authorities have issued an arrest warrant for a suspect in the case.
Vinita Smith, 55, was charged with unlawful entry after she allegedly jumped a security barrier.
The spate of incidents comes after a year in which homicides spiked in the city.
The investigation stretched from Jacksonville to Baltimore as authorities searched for answers in the wake of the violence.