I don't disagree that violence isn't the correct answer in this situation, but "Violence never solves anything" is just a nice platitude and is demonstrably false. Most of the rights and privileges we have today only came about through violent means. It is more accurate to say violence doesn't solve everything.
Or to put it another way:
The Magna Carta was a peace treaty.
The ideas of a democratic republic were born of the French and American Revolutions
MLK was the peaceful side of a civil rights movement that would not have had the same power without Malcom X and the black panthers.
Overtime, the 5 day work week, unions and most labor protections came at the expense of a LOT of blood in the United States.
Women's Suffrage was not a peaceful movement either.
In the history of most countries, mass violent protest has been the protest most likely to achieve its goals. Saying "Violence never solves anything" is to turn a blind eye to history.