A Lake Tapps pilot already facing nine criminal charges for allegedly raping and molesting two boys is also accused of sexually assaulting...

A Lake Tapps pilot already facing nine criminal charges for allegedly raping and molesting two boys is also accused of sexually assaulting four youths from Chelan County.

Chelan County Sheriff Mike Harum said his deputies have identified four local boys who say they were molested by Weldon Marc Gilbert, 47, when they were between the ages of 9 and 14.

“These are boys who lived in Chelan and Manson, who were transported by airplane to Lake Tapps,” Harum said, adding that Chelan County deputies will talk to Pierce County authorities this week about possible charges.

Harem said Gilbert grew up in Manson, Chelan County, and has property in the small community of 1,700. He now lives in Lake Tapps, Pierce County.

Pierce County sheriff’s spokesman Ed Troyer said detectives don’t know whether the four Chelan County youths are among the 20 potential victims they already have linked to Gilbert.

Gilbert appeared before federal Magistrate Judge J. Kelley Arnold in Tacoma on Tuesday for a preliminary hearing after a federal child-pornography charge was filed against him Saturday. Gilbert, held without bail, could face up to 30 years in prison if convicted on the single count, said Emily Langlie, a spokeswoman for the U.S. Attorney’s Office.

Gilbert, a pilot for UPS, was arrested Nov. 1, two days after two men reported that he had molested their younger brothers, ages 13 and 18, according to state and federal court documents.

The 18-year-old said he met Gilbert when he was 12, after his father died, and that he had been living with Gilbert for the past several months, court papers said. The man said that since 2001 Gilbert had spanked him, leaving welts, cuts and bruises on his body.

The 18-year-old said that Gilbert had a “special darkroom” in his Lake Tapps home where he “molests, ties up and spanks children for sexual purposes,” according to federal court papers. The alleged victim told federal investigators there is a switch in the room that allows Gilbert to turn on lights and a camera. Court papers said the 18-year-old stole sex tapes of himself and his younger brother with Gilbert, and his older brothers turned the tapes over to investigators.

Jennifer Sullivan: 206-464-8294 or jensullivan@seattletimes.com