Police arrested a suspect allegedly linked to a series of rapes and murders Monday in Nakhon Chaisi district of Nakhon Pathom. Officers said he matches the identikit picture they distributed.
His name was withheld. The suspect's DNA is being tested to check if it matches the DNA found on the victims, Pol Col Akkaradet Pimolsri, deputy CSD commander said.
The Central Investigation Bureau (CIB), the Crime Suppression Division (CSD), the Provincial Police Region 7 and local police have been working on the probe.
They are looking for a man who they believe has attacked 12 women in Nakhon Pathom and Sumut Songkhram provinces since 2011. Two of the victims were murdered.
Police also checked previous crime scenes to gather more evidence and speak to witnesses. Water and land routes which could have been used by the rapist were examined.
Also on Monday, Royal Thai Police spokesman Pol Lt Gen Prawut Thavornsiri advised people to be vigilant.
Children and elderly women should not be left alone, and measures to protect residents should be stepped up, he said.
Police said the rapist targets mainly elderly women who live alone. He cuts the telephone lines and power to the house, and locks the doors after committing his crimes.
The latest rape occurred in Nakhom Pathom on Sunday when a 73-year-old woman was attacked while sleeping in her bedroom.
The suspect poisoned her dog to death before letting himself in through the window, police said.
He threatened her with a knife before raping her. He then cut the telephone line and stole 5,000-baht in cash and a Buddhist amulet.
Thaweesin Wisanuyothin, director of the Galaya Rajanakarindra Institute of the Department of Mental Health, said once the rapist has been caught, background checks and psychological tests will be carried out.