TACOMA, Wash. - Police in Washington state say they believe a man arrested in Louisiana in the death of his wife was also involved in the disappearance of his young son 28 years ago.

Tacoma Police spokesman Mark Fulghum said Stanley Guidroz, 53, was never eliminated as a suspect in the 1983 disappearance of the 3-year-old boy, and now they’re more certain than before that Guidroz was involved. Investigators spent Tuesday digging in a spot along Ruston Way in Tacoma, where they believe Wallace’s body was buried, and they traveled to Houma to talk to Stanley Guidroz.

In March, Guidroz drove from Houma to Zachary, where he surrendered to Zachary police, telling the officers he had killed his wife in Terrebonne Parish and had her body in the car.

The officers searched his 1999 Ford Mustang in the rear parking lot of the Main Street police headquarters, and found on the floor of the back seat the body of Pepettra Guidroz, 47. She had been stabbed to death.

Stanley Guidroz told police he had stabbed his wife near a Burger King restaurant in Houma and then drove around for hours before stopping in Zachary.

The fatal stabbing happened after the couple apparently got into an argument.

At the time of his young son’s abduction in Tacoma, Guidroz had claimed he was taken by an unknown couple they had met in the area of the duck pond at Point Defiance Park. A search for the boy and the couple was unsuccessful.

Cold case detectives began reviewing the case in 2007. This March they learned that Stanley Guidroz had been arrested in Terrebonne Parish in the slaying of his wife.

Advocate staff writer Steven Ward contributed to this report.