A man suspected of attacking four women, killing two of them, in the Phoenix area over the past four years was arrested Wednesday, police said.

Mesa Police Chief George Gascon said the suspect is 38, lives in Mesa and has a criminal history, but he would not identify him. He has not been charged.

The public can “relax to some extent. We feel very comfortable that we have the suspect,” Gascon said.

Authorities said they used DNA evidence to connect the man to the attacks, then put him under surveillance for about a day before arresting him Wednesday afternoon.

The nude body of Karen Jane Campbell, 44, was found on a roadway in October 2007. The partially clothed body of Alisa Marie Beck, 21, was found in an alley in 2004 about five miles away. Both had been strangled.

DNA helped police connect the killings in December. At the time, they said that both women had a history of drug abuse and prostitution, and that neither had a home.

Police used DNA evidence again this month to connect the killings to an assault in which a 47-year-old woman was taken to a Mesa home in August and raped before she escaped and flagged down a cab.

The latest attack to be linked to the crime spree occurred Nov. 4 when a 35-year-old woman was kidnapped, taken to an alley in central Phoenix, raped and beaten. Police said investigators believe the woman was left in the alley for dead. She survived with injuries to her head, neck and torso, police said.

Investigators said the suspect was previously arrested for soliciting prostitutes and fit a police description.