HOUSTON -- A UPS driver arrested and charged in connection with a slaying from 16 years ago may be involved in the murders of two other women, police told KPRC Local 2.

Edward George McGregor, 33, was arrested at work Monday in a Missouri City case. Investigators said in 1990 he stabbed Kim Louise Wildman, 38, in her home in the 1400 block of Whispering Pine Drive.

Houston police investigators believe McGregor is responsible for the killings of Danielle Subjects, 28, of 10965 South Gessner, and Mandy Rubin, 25, of 10750 Westbrae Parkway.

Both women were strangled, beaten and found in their apartment bathtubs. Subjects was found on Aug. 5 and Rubin on Feb. 4. Their apartment complexes were four blocks apart. McGregor lived in the same apartment complex as Rubin.

"The women were left in the same situations, same physical posing of their bodies, same areas of their house and bathtub. It wasn't just a random thing that they both happened to die like that," said Sgt. Jim Binford with the Houston Police Department.

Rubin's family told KPRC Local 2 that McGregor and Rubin were friends. He attended a party at Rubin's mother's home.

"She was friendly to everybody," said Tina Rubin, Mandy Rubin's cousin. "It was somebody that knew her, that knew her children, that knew her family. It was just a shock. It's still a shock."

Rubin left behind two children, 4 and 6 years old.

McGregor has not been charged with the two murders. For now, police are only calling him a suspect.

Officials said that because there is a 16 year gap with three known victims, investigators believe McGregor is likely responsible for other violent crimes against women. The crimes could vary from assault to sexual assault to murder.

HPD investigators are researching open cases to try to determine if McGregor can be identified in other incidents.

"I’m sure he befriended a lot more women that just my cousin and then that other lady that was also murdered in the same fashion, so it's just really scary," Tina Rubin said.

Police said they do not believe McGregor met his alleged victims through his job as a delivery driver.

Anyone with information on McGregor is asked to contact the Homicide Division at (713) 308-3600 or Crime Stoppers at (713) 222-TIPS.