Looking for ideas on where to go from most recent quest

My group took a quest from the wealthiest man in the area, who's parents had died from unknown circumstances, he was asking them to get his pet back for him. A group of bandits from a shady guild had also been hired to search for the pet as well in case they had failed, but it looked like they had all been killed. They managed to find the leader floating in the middle of a lake and revived him to help guide them to the pet's whereabouts. The pet was revealed to be an Owlbear that had taken residency in the large woods behind the home. The Owlbear turned out to be a mother and had given birth to 3 cubs which all took to the group's Gnome Wizard. Having bonded with them they were a little apprehensive about returning the Owlbear, but knew it was what they were hired for and it was the right thing to do. The leader of the bandit group revealed his guild had been hired by this man previously to kill his parents so he could collect the inheritance. They also came to find out the man was going to kill the Owlbears to make a coat for himself and they didn't want that, now knowing what they did. After a brief fight they knocked their employer out and left him in his mansion with the Owlbears to deal with. One of the members of the group, a tiefling warlock, felt they shouldn't have left just left him there and decided to go back there that night along with the group's rogue to investigate. When they got to the mansion they found it completely empty, only signs of scrapping on the floors and walls with no trace of blood. They decided to check the attic where they found several bodies all belonging to people who had been reported missing from the local town. Coming to the conclusion the man they had been hired for was in fact psychotic they've resolved to go hunt him down and stop him before he can murder anyone else.

Just looking for ideas on where to go for this! I have some thoughts but would love input. Thanks!

tl;dr: Group was hired by town rich guy who is actually a murderous psychopath. Now on a quest to find and stop him.