Last Updated Jan 18, 2018 2:25 PM EST
PHOENIX - Phoenix police say a convicted felon suspected in the slayings of his mother and another man is behind seven other recent killings. Police speaking at a news conference Thursday morning said 35-year-old Cleophus Cooksey went on a killing spree between Nov. 27 and Dec. 17, 2017, ultimately taking the lives of nine people in Phoenix and the suburbs of Glendale and Avondale.
And Phoenix Police Sergeant Jonathan Howard told reporters that there is "a distinct possibility" Cooksey may have killed others who they have not yet identified.
Cooksey, who Howard said had previously served 16 years in prison for manslaughter and armed robbery, was arrested Dec. 17 at the scene of the shooting deaths of his mother and stepfather in the couple's home. According to CBS affiliate KPHO, Cooksey was released from prison on July 28, 2017.
Officials say investigators were able to use evidence from shell casings to connect at least some of the killings, and that new technology allows police to get results of ballistic checks within hours instead of weeks and to more easily find connections between cases.
Police say they have not been able to establish a motive or connection between Cooksey and the victims in several of the homicides, and are hoping people in the community will reach out with information that will help them further understand the crimes.
Police said Cooksey's alleged spree began on Nov. 27, when Phoenix police found Andrew Remillard and Parker Smith shot to death in a vehicle. Then on Dec. 2 at about 7:45pm, officers found Salim Richardson dead of a gunshot wound. The suspect had allegedly fled the scene and police said Richardson's handgun had been stolen from him.
On Dec. 11 in Avondale, police found a man named Jesus Real dead from a gunshot wound inside an apartment complex. Again, the suspect had fled. Police connected Cooksey to this case through Real's sister, who they discovered Cooksey had a relationship with.
On Dec. 13, police were called to the scene of a shooting at a Glendale apartment complex and found LaTorrie Beckford, who died soon after being discovered. Two days later, on Dec. 15, they discovered gunshot victim Kris Cameron in Glendale. Cameron died soon after police arrived and police say he may have been in the area to do a drug deal with Cooksey.
The next morning, the body of Maria Villanueva was discovered in Phoenix. Police say they believe Cooksey kidnapped her in Glendale on Dec. 15, then sexually assaulted and killed her.
Finally, on the evening Dec. 17, CBS affiliate KPHO reports that officers were called to Cooksey's mother's home after witnesses reported hearing gunshots.
The first officer on the scene reportedly saw blood on the patio in front of the door, as well as on the security door.
"The officer did not see any casings or blood trail leading from the apartment, which made him believe the injured person may still be inside the apartment," according to court documents.
According to the probable cause statement, Cooksey answered the door when the officer knocked and said he was alone in the apartment.
The officer reportedly asked Cooksey to step outside, which he did "but opened the door just enough for his body to fit through so the inside of the apartment was not visible" and then closed both the door and security door.
The arresting officer said Cooksey told him the blood on the patio and door was his, explaining that he had cut his hand.
"He told the officer he washed the blood off and he was better now," according to the probable cause for arrest statement.
At that point, the officer decided to detain Cooksey.
"Cooksey became upset and began yelling, 'I'm the strongest man alive,' and 'I'll cut your throat,' and 'I control the gun.'"
Once Cooksey was detained, officers went into the apartment and discovered the bodies of a man and woman. Both had been had been shot to death.
Howard said a combination of physical and forensic evidence and witness statements enabled investigators to link Cooksey to all the killings.
"I'm just proud as heck that he's off the street," said Glendale police Chief Rick St. John.
The FBI and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives provided support for the local agencies' investigation, officials said.