The Texas Chain Saw Massacre

Mostly luck based. You must play as a character from the family. Cannot be done as Leatherface. EDIT AmitySpells comment suggests Cook or Johnny as they have the higher starting Savagery stat. END EDIT Can be done in private matches which is the easiest method.

Victims must have a BONE SCRAP. At close range, victims can use these to sneak attack family members from the back or intiate a grapple if they trigger it from the front.

PUBLIC MATCHES

This is the luck based part. Victims have to intiate the close encounter and they must have a bone scrap. Once the grapple is engaged spam as fast as you can. After a few seconds a winner is determined.

If the family member wins an animation plays out of the family member killing the victim. If the victim wins an animation will play of the victim stunning the family member and they will have a few seconds to escape.

If another family member interrupts your grapple they will get an instant kill against the victim and you will NOT get progress towards this.

PRIVATE MATCHES

In a private match you will need at least 4 players to start a match. One player must be Leatherface. Pick from Hitchhiker, Cook, Sissy or Johnny. The other players should fill the victim side. Pick a map you are familiar with and pick a meeting point.

Victims should make as much noise as possible to wake grandpa so the family can open the basement doors. Victims should also grab one bone fragment each.

Victims approach the non-Leatherface family member from the front and press to start the grapple. The family member repeatedly presses while the victim presses nothing. Once the family wins the close encounter the victim will be killed and one tick towards the achievement should be earned.

This can be done in public or private matchs. A close encounter happens when a victim has a bone shard and stabs a family member in the chest, not the back. Once stabbed in chest the button appears on your screen and the victim and the family member has to tap the A button as fast as possible. For this achievement the family member has to win the close encounter and after winning the family will execute the victim. The victim needs to stab the family member in the chest with bone shard, if stabbed in the back it will only be a sneak attack.

Couple of tips, start a a private match. You need 4 people to start a match. One has to be leatherface the one going for achievement needs to pick another family member and the other 2 play as victim. Start of match have victims make as much noise as possible to wake up gramps. Once grandpa wakes up have leatherface open up blue basement doors and have victims grab bone shards. Meet up in the house and have victim stab the one going for the achievement in chest, not the back. Family press fast as possible and victim just does nothing. This also counts as an execution.