You can find the House on a Hill Cyberpsycho Sighting way out in the boonies to the east of Night City. It is a small house surrounded by a fence with security wire on the top. There is a gap you can sneak in through, which is useful.
The Cyberpsycho is one Sam Milton, an army veteran who is actually quite tough, with a robust health bar and plenty of security in place. There are two drones you will need to deal with, one near the gap in the fence and another at the far side of the house. There are also two turrets on the roof of the house that will cause you problems unless you hack them.
When you have hacked all of the drones and turrets, it is time to deal with Sam Milton himself. If you find yourself struggling in this fight, you can find some refuge by jumping up on the roof of the shed at the back of the house. Hitting Milton with the Overheat hack is a solid option to do some damage to him, and if you have Weapon Malfunction you can really interfere with his ability to do damage.
System Reset will shut him down completely, which is a great option if you have it. Milton moves fast and is armed with a shotgun that will do a lot of damage up close. If you have Mantis Blades then the good news is that you can stun locked him with a full combination, and he will stand there while you chop away at his health, unable to get a shot off.
If you find yourself being chased around the area by him, make sure you steer clear of any explosive hazards in the yard, or his shotgun will most likely set them off and kill you.
Once you have dealt with Milton head around to the front of the house where you will find two bodies lying on the ground. Interact with them both to collect the evidence you need, then text Regina to fill her in on the details.