Don't move! I've called the police!
'Muova' = MWOH-vah — formal imperative of 'muoversi'; the 'uo' is a diphthong.
Use when the other driver or a suspect attempts to flee the accident scene before police arrive. Witnesses can hear you and police on the phone can note the situation.
You cannot physically detain someone after an accident, but you can assert authority verbally. Stating that police have been called may deter a fleeing driver. If they flee anyway, immediately give police the direction of travel and any vehicle details.
Non lasci il posto! È obbligato a fermarsi!
Don't leave the scene! You are required to stop!
States the legal obligation — may remind the driver of their duty.
La sua targa è già stata fotografata.
Your plate has already been photographed.
Informs the driver that flight will not prevent identification.
Ci sono testimoni! Tutti hanno visto!
There are witnesses! Everyone saw!
Appeals to social accountability — effective in populated areas.
Italian law art. 189 CdS: leaving the scene of an accident with injuries (fuga) carries 1-3 years imprisonment and immediate licence revocation. Even if the driver is eventually identified, charges are not dropped — the flight itself is the crime.