Details of Disappearance
Marks accompanied her mother to the San Joaquin County Mental Health Department in Stockton, California on October 18, 1988. Her mother was employed at the department. Marks then walked alone to the Department of Motor Vehicles (DMV) on Parks Street to get an identification card.
She is known to have arrived at the DMV, because her card was mailed to her several days later. Marks called her mother at work after leaving the DMV. She was unable to reach her and left a message on the answering machine. During the message she didn't sound as if anything was wrong. She has never been heard from again.
Marks was supposed to meet a friend before she began work at 5:00 p.m., but did not keep the appointment. She did not take any personal belongings besides her purse when she went missing. She never retrieved her last paycheck from her place of employment, Rick's New York Style Pizza, where she was a waitress.
Wesley Howard Shermantine Jr. and Loren Joseph Herzog, the so-called "Speed Freak Killers," are possible suspects in Marks's case. They were arrested in 2000 and ultimately convicted of murdering several females in the 1980s and 1990s; authorities believe they had as many as fifteen victims. Photographs of both men are posted with this case summary.
Shermantine is on death row. Herzog's sentence was reduced from 78 years to 14 years after the court ruled his confession had been coerced. He was paroled in 2010 and then took his own life in January 2012, after he found out his former partner had begun cooperating with authorities and had offered to reveal the location of victims' bodies in exchange for a payment of $33,000.
Shermantine led investigators to the skeletal remains of Chevelle Wheeler and Cyndi Vanderheiden, who'd been missing since 1985 and 1998 respectively. He also pointed out an abandoned well in Linden, California that contained some 300 human bones and personal items. Shermantine stated the well contained up to twenty victims. He blames Herzog for all the murders and says he only helped with disposing the bodies.
Shermantine and Herzog are being investigated in other missing persons' cases, including Phillip Martin
, Michaela Garecht
, Susan Bender
, Sylvia Standly
and Ruth Leamon
. The skeletal remains of victims Kimberly Billy, a 19-year-old who disappeared in 1984, and Joann Hobson, a 16-year-old who disappeared in 1985, were identified, but Standly's body was not found in the well.
Foul play is suspected in Marks's case. She had moved to California only a few months prior to her disappearance.