TULSA, Oklahoma - Police are investigating four murders within 24 hours in the Tulsa area. They say it's a very rare occurrence and they don't know yet if the cases are connected.

The important thing to know about the murders is they are not random acts of violence, the targets were very specific. That doesn't lessen the fact that four people are dead, but should make people feel safer about being in Tulsa.

Police say the first murder is a drug debt situation.

They say a woman knocked on a door at the Somerset Apartments in order to get the men to open it; once they did, a man wearing a bandana mask shot one of the guys in the neck.

Police quickly arrested Cory Keubler.

"That case is broke because Somerset has excellent video cameras, none like I've ever seen before," said Sergeant Dave Walker.

The next murder involves two victims and happened 15 hours later.

Police found a man and woman shot to death near the master bedroom. Detectives initially can't figure out why there's blood all over the house.

"Turns out the family dog got shot three times and was running through the house," Walker explained.

They say the scene seems personal because of the overkill - the victims were shot many times, furniture was broken for no reason, and two different caliber guns were used. Plus, the woman killed is associated with the man arrested in the first murder.

Then, seven hours later, the fourth murder. This time, it's the suspect who gets killed.

Walker said, "He's a one-man crime spree."

They say he shot a woman, who will survive, stole her car, set it on fire, kicked in doors, then, kidnapped some men, drove them to a home and told them they were going to die; but they fought back, took his two guns away from him and shot him.

"Those people in that car at that time are heroes to us,” Walker said, “because that guy could've gone on."

Police will now test the guns to see if they're connected to the other scenes. Police say they are also looking into some Irish mob gangster connections as well.