In the video game Grand Theft Auto 5, one of the quick crimes you can commit to earn some money is robbing an ATM. This small-time crime can net you between $30 and $120, which is higher than the usual $10 to $20 you might grab from robbing pedestrians. While you can’t directly rob the ATM itself like you would an employee, you can steal money from people after they've used it. This can earn you anywhere from a few dozen to a few hundred dollars. This guide will show you how to rob people after they use the ATM in Grand Theft Auto 5.
Steps

Find an ATM. There are several ATMs scattered across the map. Typically, you will find ATMs near banks, gas stations, convenience stores, and other commercial businesses. Some ATMs can be found at the Xero gas station in Pacific Bluff, west of Los Santos. Another ATM is located near the bank in Little Seoul, in the city area of Los Santos, and there's one at the Fleeca bank in Banham Canyon.

Wait for a pedestrian to use the ATM. Once you find an ATM, you need to wait until a pedestrian approaches and uses it. Do not attack the pedestrian while they are using the ATM. Wait until they’ve finished withdrawing money.
If you stand too close to the ATM, they might get scared and leave, preventing you from getting any money.

Follow the pedestrian. Once the pedestrian has used the ATM, quickly move behind them and begin following the path they take. Keep following them until there are no witnesses in sight or at least until there are no police nearby who could catch you.

Take down the pedestrian. Once you feel safe, take down the pedestrian who just used the ATM. You can either shoot or knock them out.

Pick up the money. After the target is down, they will drop the money they just withdrew from the ATM. Simply walk over the money to pick it up.

Leave the area. Ambulances and police will arrive shortly after you take down the pedestrian. Get back in your car and quickly drive away from the area to avoid being caught. Then, you can drive to the next ATM and continue robbing. If any witnesses saw the incident, you need to hide from the police until you're no longer wanted.