Skids 0XP

Leo De Luca - No brainer, an extra action is great but he is expensive. If you get him early he can pay for himself in time and if you get him later then you should have a fair amount of resources anyway. May be worth going to 2x in order to see early.

.45 Automatic has the edge over the Derringer for more ammo and guaranteed +1 damage.

Burglary will drop to 1x once have enough experience for Hot Streak.

First Aid isn't bad if you can spend a turn healing.

Flashlight really secures the ability to investigate.

Machete if you run out of bullets this is a solid backup.

Physical Training over Hard Knocks because being stuck with Frozen in Fear sucks and it shores up a weakness rather than pushes a strength.

Pickpocketing although I find I'm mostly fighting over evading it's not a bad card when you have to duck out of the way and always a good dump to Crypt Chill.

Backstab +2 damage is great

Emergency Cache these are the only way you'll really get out of losing XP to Hospital Debts, keep even after obtaining Hot Streak

Evidence! is a great way to get two actions for one, also helps with high shroud areas.

Sneak Attack alas, doesn't drop Gandalf in and will allow attacks of opportunity if other enemies are engaged but a guaranteed 2 damage is strong

All the skill supports are there to ensure you don't get in too much trouble. No Guts though could swap 1x Unexpected Courage for it.

Opportunist is really flexible, so just view it as a one-time +1 on checks you are weak against or possibly a guaranteed success on things that you are strong in.

Vicious Blow is necessary to kill tougher enemies.

Pretty much it.

With this build I was able to do 14 damage in 1 turn to an enemy, though had a lucky run of cards to do so.

You can watch it here in the finale of our playthrough - https://www.youtube.com/watch?v=vvjpG93IBiY

Leo +1 action, pay 2 for +1 action, Lita (controlled by another investigator) for +1 combat and +1 damage

1 - Attack with automatic, Overpower, success, 3 damage 2 - Attack with automatic, Vicious Blow, Vicious Blow, success, 5 damage 3 - Backstab, Manual Dexterity, success, 4 damage 4 - Evade 5 - Sneak Attack, 2 damage

The enemy in question already had 1 damage and 14 more was enough to kill them, thankfully. Likely to never be repeated.