Benvolio
By fighting with Mercutio, Tybalt incurred the death sentence according to the edict promulgated by the Prince in Act 1 Scene 1 which made fighting in the streets a capital offence. Montague argues that Tybalt's life was forfeit anyway and that Romeo was just carrying out the sentence of the law.
Romeo kills Tybalt in Act III, after Tybalt has killed Mercutio in a duel.
The first time he hears that Tybalt wants to fight him in a duel, Tybalt is his cousin by marriage, although only Romeo knows this.
You mean, "How does he justify his murdering Tybalt?" The only person who offers a justification for Romeo's actions is Benvolio, who argues that in killing Tybalt Romeo was only carrying out the law, since Tybalt had committed a capital crime in killing Mercutio. Juliet does not attempt to justify Romeo's actions, since she does not know the details anyway. She does feel she has to make a choice between loyalty to family and loyalty to her husband and she comes down firmly on the side of her husband.
When Romeo and Tybalt first meet, Romeo tries to defuse the tension and shows kindness towards Tybalt. He refers to Tybalt as "cousin" and expresses his love for Tybalt's family (Juliet's family) to avoid confrontation. Romeo's actions are driven by his recent marriage to Juliet and his desire to keep peace between the two families.
She is at first very angry with the guy who killed Tybalt, until she realizes that he is her love and her husband Romeo.
Tybalt is Juliet's first cousin, being the son of Mrs. Capulet's brother. By marrying Juliet, Tybalt then also becomes Romeo's cousin by marriage.
Tybalt is now Romeo's wife's cousin, thus making him a relative of Romeo. This is why Romeo refused to fight Tybalt at first, which leads to a chain of events that eventually forces Tybalt to flee. To clarify: Romeo is Tybalt's cousin-in-law.
Montague, who acts as Romeo's advocate at the trial, argues that Tybalt had already broken the law and incurred the death penalty by killing Mercutio. Romeo was therefore only carrying out the law by punishing Tybalt. "His fault concludes but what the law should end, the life of Tybalt." The Prince has no desire to encourage vigilante justice, so he does not acquit Romeo on this plea, but only reduces his sentence from death to banishment
Romeo killed Tybalt after Tybalt killed mercutio.
tybalt recognized romeo at the party
romeo