The car belonging to murder suspect Shauntez "Shaun" Hairston was found Friday by Davenport Police in the 700 block of W. 14th Street, Capt. David Struckman said.

Hairston is accused of killing 20-year-old Marissa Tharp of New Boston. Her body was found Tuesday in a trailer home in Alorton, Ill.

Hairston is charged with first-degree murder. He is being held in the St. Clair County Jail in Belleville, Ill. His bond has been set at $1 million.

Tharp was last was seen Monday when she left her job as a waitress at Flood Waters in Muscatine. She later called her family late Monday from Davenport saying she was heading home.

Davenport police records show Tharp and Hairston were involved in a dispute in April. Police were called to Motel 6 in Davenport to settle an argument between Tharp and Hairston, an ex-con whom police say she had been dating for more than a year at the time.

Thursday, Hairston was charged with first-degree murder for the beating and strangulation of Tharp, a college co-ed who called her parents Monday night to say she was on her way home from Davenport. By early afternoon Tuesday, her body was discovered in a dilapidated mobile home in Alorton, Ill., a tiny community located near East St. Louis.

And police in the Quad-Cities have begun assisting authorities in southern Illinois in the case, including trying to locate Hairston's car.

Davenport police Capt. David Struckman said his department is helping the Illinois State Police, "gather evidence that may be useful in the case."

He said the department had contact with Tharp and Hairston in April when she filed a theft report. According to that report, Struckman said the two were at the Motel 6 in Davenport. "He accused her of stealing money from him," Struckman said. "He searched her and took her car keys from her. She called us and we got her car keys back for her. She didn't want to press charges."

Hairston was being held Thursday in the St. Clair County Jail in Belleville on $1 million bond.

Tharp last was seen Monday when she left her job as a waitress at the Floodwaters restaurant and lounge in Muscatine.

Her father, Kenny Tharp, said his daughter called her mother about 11:30 p.m. Monday and said she was going to watch the fireworks in Davenport. "She talked to her sister about midnight and said she was on her way home," he said. "We waited and waited for her and she never came."

He was in the process of filing a missing person report when police discovered his daughter's body.

Illinois State Police Master Sgt. James Morrissey, based in Collinsville, said Thursday that investigators still were trying to piece together how Marissa Tharp ended up in the East St. Louis area.

"Whether she drove herself down here or was abducted, we still don't know," he said. Tharp's car was located in East St. Louis, he said, but the search is on for Hairston's car.

"We've contacted law enforcement in the Quad-City area and provided them with a vehicle description that we believe Mr. Hairston may have had at the time," Morrissey said. "We're asking law enforcement to check for this vehicle."

Meanwhile, more information about Hairston and Tharp surfaced Thursday.

Police reports from other jurisdictions show that both Tharp and Hairston each had called police numerous times in recent months, accusing each other of harassment.

Kenny Tharp said his daughter had met Hairston while she was a student at Southern Illinois University-Edwardsville, or SIU, where she was a student in 2003 and 2004.

Campus officials there said Hairston never attended the university. On Thursday, campus detective Justin Lieberman said Tharp had called police there in February from Macomb, Ill., where she moved after transferring from SIU to Western Illinois University for the 2004-05 school year.

She alleged that Hairston had hit her in the arm when the two were in a car together during her visit to the SIU campus on Feb. 5. Lieberman said Tharp said she was in Edwardsville visiting friends. No charges were filed because Tharp called 10 days after the alleged incident and wouldn't make an in-person report, Lieberman said.

Hairston has served three prison stretches for numerous felony convictions and parole violations dating to 1999. He was convicted of aggravated assault and drug possession in Madison County. He was also convicted of possession of a weapon by a felon in Champaign County in 2002. He was discharged from prison last September.

The suspect's father, Kenneth Hairston, said his son had introduced Tharp to the family as his girlfriend. "They had been together for a while, I think on and off," the elder Hairston said.

Kenneth said his wife did upholstery work at the mobile home where Tharp's body was found, and that his son sometimes spent the night there. Kenneth said he and his wife had gone to the trailer Tuesday morning to pick up some material. He said they encountered an agitated Shaun pacing outside the trailer.

"He was very upset and didn't want us to go in the trailer," Kenneth said. "He said he'd gotten upset at her (Tharp)."

The elder Hairston said he and his wife become concerned and drove to the Alorton police station to suggest they check the trailer.

The town of New Boston remained in shock Thursday over Tharp's death.

Amber Houston of New Boston, said it has been a weird week. She recalled that on Sunday she had thought about her friend and former Westmer High School classmate, Marissa Tharp, and was wondering what she was up to.

"The last time I saw her was not long after graduation," said Houston, the 2003 class salutatorian.

Houston said she was on the freshman volleyball team with Tharp, and that Tharp was Student Council secretary-treasurer their senior year. They also were inducted into the National Honor Society together their senior year.

"She was just a sweetie," Houston said. "She was very beautiful and very personable."

Houston said she was at work Tuesday when her sister called her and told her of Tharp's death.

"I didn't believe it," she said. "People in this community, we don't deal with this issue. So when we find that it has happened to one of our own, it's a shock. I had to watch the news to make sure."

On Thursday, Kenny Tharp continued to prepare himself for the case.

That Hairston has been charged with first-degree murder, "is a big plus," he said. "As far as where the case goes now, that's beyond my control. I do realize that it's going to be a long and drawn-out process and that the next 12 months are going to be hell."

Throughout the day, he said, people who knew and loved Marissa had been streaming in and out of the house.

"It didn't matter who you were or what you looked like, she was decent to everybody," he said. "If there was an All-American girl, she was right up there with them."