Ideally, we wouldn't deploy a branch of the military against citizens at all even if nothing bad happened in this instance.
Marines were deployed during the 1992 riots and a miscommunication resulted in them firing 200 rounds into someones house[0].
> According to the book “Fires and Furies” by Maj. Gen. James Delk, who oversaw National Guard operations in California at the time, Marines caused an incident when they accompanied police officers to a domestic disturbance in the wake of the riots.
> A police officer asked the Marines to “cover me” as he tried to enter the residence, according to the book. Instead of simply pointing their weapons at it to deter the people inside, the Marines opened fire on the house.
> “The officer had not meant shoot when he yelled ‘cover me’ to the Marines,” Delk wrote.
0: https://www.yahoo.com/news/los-angeles-officials-fear-marine...