Probation violator Willie James Parker Jr. has been eluding Prince William County sheriff's deputies for two years. So they went to the public to find him.

Earlier this year, deputies put up picture posters of Parker at about 75 convenience stores and small businesses around the county, hoping one of Parker's friends would see his picture and make a telephone call to let police know where he is.

Parker -- who has been sought since October 1988 on a probation violation on an involuntary manslaughter conviction for killing his brother -- is one of 23 Prince William probation violators who have been pictured on wanted posters on the orders of Sheriff Wilson Garrison.

"We are not sure Willie is still even in the area," said Capt. William Woolf. "But what we are hoping is that someone from here, D.C. or Alexandria will see this poster and give us a call and tell us where he is. He violated his probation and justice must be served."

The Prince William County Sheriff's Department is believed to be the only Washington area police agency using a poster program for probation violators. Several police departments said they periodically print posters for crime suspects, but those posters are usually disseminated only to government buildings and police agencies.

Of the 13 probation violators pictured on posters in Prince William from January to August, nine were apprehended. Ten new posters put up in September netted two arrests and tips that are still being investigated, according to the sheriff's department.

"We get a lot of tips from the posters in 7-Eleven stores," Garrison said. "It seems like a lot of these people {violators} know people who hang out in 7-Elevens."

Garrison said he got the idea for the wanted posters after noticing how successful the syndicated television show "America's Most Wanted" was in helping the FBI find crime suspects.

The sheriff's department took over responsibility from the county police for apprehending probation violators in 1985, when three people failed to follow probation guidelines. The number of violators increased from five in 1986 to 150 in 1989. So far this year, 434 probation violators have been identified, sheriff's statistics show.

"The posters seemed to be an effective or quicker way to apprehend these people to alleviate manpower hours, instead of having deputies going out beating the pavement," Garrison said.

The poster subjects include persons wanted for violating their probations on drug, theft and violent offenses. The posters are emblazoned with the word "WANTED," followed by a complete description of the violator and a black-and-white photo.

The posters have netted tips on violators as far away as South Carolina, where Kimberly Ann Herndon, 30, of Manassas, was apprehended. A friend called to tell police that Herndon, wanted for violating probation on a drug possession conviction, had fled to Myrtle Beach, said Deputy Linda Olson.

One poster subject called Woolf to complain when he found out that his photo was posted around the county. "He said, 'You all have my poster up all over Manassas. I don't want it up. Take it down,' " Woolf said. "I told him to turn himself in and we would take it down. He came on in, and like we said, we took it down."