Cop & ½ (1993)

After an 8-year-old boy witnesses a murder, he agrees to help the police only on one condition: they have to make him a cop, too. Paired with the pint-sized, streetwise new recruit, a hardboiled officer finds himself stuck with an unlikely partner. As time runs short, the veteran cop must learn to take the kid seriously while they work to track down the criminals and bring them to justice.