Drops of blood and grains of sand.
These are two of the things that led authorities to charge Benjamin Michael O'Donnell in the slaying of Tracy Ann Carson.
After eight months of investigation and a manhunt that ended halfway across the country, Waterloo police formally charged O'Donnell, 22 and formerly of Evansdale, for first-degree murder Monday.
O'Donnell remains in the Monterey County Jail in California where he was arrested June 7 for violating probation on prior Iowa charges. Bond for the murder charge is set at $2 million.
"At this time, with the progress of our investigation, we felt it was appropriate now so the California authorities had the whole picture of what was going on," Waterloo Police Chief Tom Jennings said. "Up until this point, we have not had enough to charge him."
O'Donnell waived extradition proceedings during a Monday afternoon hearing, and Waterloo police are making arrangements with the Black Hawk County Sheriff's office to bring him back to Iowa.
Reached at her home in Minnesota, Jolene Stock, Carson's sister, said she had been told about the arrest but declined to comment.
O'Donnell's grandfather, Martin O'Donnell, referred questions to public defender Dave Staudt, who was not available Monday or this morning.
Carson's death has been ruled a homicide by Dr. Julia Goodin, but police said the actual cause of death will not be known until tests are completed by the state Division of Criminal Investigation lab.
"We are still doing some toxicology reports," Jennings said. "Other reports we have not fully received from the state medical examiner."
The condition of Carson's body -- partially clothed -- suggests a sexual assault or attempted sexual assault occurred, according to court records.
DNA analysis determined traces of blood found in the trunk of O'Donnell's car were "consistent" with Carson, records state, and officers are drawing a connection between sand found in his home and the sandy area where Carson's body was found in April.
Jennings declined to explain how O'Donnell and Carson knew each other. Although the investigation is continuing, Jennings doesn't expect charges to be filed against others.
Along with Waterloo police, officers with the Black Hawk County Sheriff's Office, Evansdale Police Department and the Monterey County Sheriff's office assisted in the investigation.
Carson, a mother of three who worked as a receptionist for Community Motors in Waterloo, apparently left her 40th birthday party at Paulie's Place on La Porte Road Oct. 6 without telling anyone. Police and family members began searching for her when she failed to return home the following day.
Detectives honed in on O'Donnell early in the case after witnesses placed the two together. While Carson was still missing, officers admitted in court they had investigated O'Donnell in Carson's disappearance and described him as one of the last people to see her.
However, details in the criminal complaint against O'Donnell shed new light on the investigation going on behind the scenes.
Carson left the party with O'Donnell and one of O'Donnell's friends and went to another bar, according to court records. From there, they went to the unnamed friend's home in Evansdale, where Carson exchanged words with O'Donnell. Carson then left with him, presumably to be taken home.
Four days into the missing persons investigation, O'Donnell told police he left his friend's house with Carson on the night in question and left her back at Paulie's Place, records state. Police said they were unable to locate anyone that could verify O'Donnell's version of the events.
Officers also asked O'Donnell about the possibility of his fingerprints being on items from Carson's purse found discarded along old Highway 20, according to court records, and he gave several conflicting versions of how his prints could be on the items.
Lt. Bruce Arends declined to say if fingerprints were actually found on her belongings.
A search of the Evansdale home O'Donnell shared with his grandparents turned up a pair of pants covered with sand inside the washing machine, according to court records. Traces of blood were found in several areas of the trunk of the Mercury Sable O'Donnell was driving on the night of the disappearance.
That same day, police took O'Donnell to a local hospital to execute a search warrant for "body specimens," and officers discovered a cut on his wrist, records state. O'Donnell told investigators the injury happened earlier that day, but an emergency room doctor placed the time frame for the wound closer to date Carson disappeared, records state.
At that time authorities did not have enough evidence to arrest O'Donnell in Carson's disappearance -- her body had not been discovered. But police found marijuana stems and seeds in an ashtray, a "No Parking Fire Lane" sign on his wall and a spent rocket tube on the floor of his bedroom and took him into custody on drug and weapons charges.
The weapons charge was later dropped, but he pleaded guilty to marijuana possession, illegal possession of a traffic device and violating probation in a 1998 lottery fraud charge. In February, he was sentenced to serve two to five years of supervised probation.
Several months passed before the next break in the case. A fisherman discovered Carson's body in a backwater of Crane Creek just off a bridge near Dunkerton April 25. Investigators believe she was buried, but high water uncovered her body.
Sources later told police the place where the body was found was one of O'Donnell's fishing spots.
Authorities said O'Donnell fled Black Hawk County soon after word of the fisherman's discovery began to spread.
Police tracked him to a mobile home park in Lockwood, Calif., where he has family. Officers arrested him June 7 for violating his probation and Waterloo police submitted the paperwork to charge him with murder the following day.
O'Donnell, who had worked as a saw operator at Bertch Cabinets in Waterloo, had minor scrapes with the law in the past.
The lottery fraud charge stems from a Nov. 27, 1998, incident were he allegedly tried to redeem a lottery ticket taken during a burglary at Family Mart in Raymond, records state. He tried to pass the card at Express Mart in Evansdale.
On June 22, 1998, University of Northern Iowa police stopped him for speeding at University Avenue and College Street. He was charged with possession of marijuana after officers found Zig Zag cigarette papers in his glove box along with a pipe, stems and seeds.
Evansdale police arrested him Feb. 8, 1999, after they found a pipe containing marijuana residue. He was sentenced to one year probation and had to apply for a temporary driver's license to drive to work, according to court records.