DURHAM, N.C. — The police crime scene technician who collected evidence after novelist Michael Peterson's wife was found dead at the bottom of a staircase took the witness stand Wednesday for a fourth day.

And the defense isn't done with him yet.

Dan George clearly wanted to be anywhere other than where he was as defense lawyer David Rudolf asked seemingly endless questions in an effort to persuade jurors that police made too many mistakes for evidence analysis to be useful.

Dan George testifies Wednesday.

Prosecutors contend that blood spatter evidence suggests Michael Peterson used a fireplace poker or similar object to kill his 48-year-old wife and then staged the crime scene to make it look like she fell down the stairs.

Jurors have yet to hear from the prosecution's blood spatter expert, but it took George four days and some friendly advice from the judge — suggesting that the expert was better qualified than George — to discuss the significance of blood wipes, swipes, smears and spatters.

Rudolf finally got frustrated and told the witness he wouldn't be allowed to step down until he gave straight answers.

"Sir, I am going to ask the same question over and over again until you answer my question. Do we understand each other?" Rudolf asked.

It sometimes took three or four questions, but Rudolf eventually got his answers. During seven hours of cross-examination over three days, George testified that:

• He noticed blood on a cordless telephone, but did not seize it into evidence;
• He did not seize Kathleen Peterson's clear plastic sandals because he did not see any blood on them;
• Michael Peterson's bloody shorts and shirts were put in the same evidence bag;
• Blood-soaked towels and paper towels found around the body were not taken into evidence;
• Few notes were taken, and single-paragraph narratives encapsulated hours worth of crime scene work;
• He found evidence of blood transfer and other scene contamination caused by police;
• Michael Peterson's shoes and socks had little blood on them — if he was wearing them while attacking his wife with a weapon they should have been blood-soaked;
• Three police officers saw bloody footprints invisible to the naked eye but visible when the chemical luminol was applied, although the reaction was neither photographed nor mentioned in his initial report.

Prosecutor Jim Hardin Jr. will try to rehabilitate his witness Thursday when George takes the stand again. George's testimony is expected to set up that of a North Carolina State Bureau of Investigation agent who analyzed blood spatter patterns in the stairwell where Kathleen Peterson died.

Prosecutors maintain there is evidence of "cast-off" blood — patterns created when a bloody object is brought back and forth forcefully, as in an attack.

The defense claims the hallway was too narrow for a fireplace poker to be used, no evidence exists that a fireplace poker even was even kept in the house, and many police officers and civilian witnesses were in the stairwell before the agent analyzed it.

Testimony resumes at 9:30 a.m. Thursday. The trial is being broadcast by Court TV.