DURHAM, N.C. — Robert Petrick searched for the words "neck," "snap," "break" and "hold" on an Internet search engine before his wife died, according to prosecutors Wednesday.

More than two years after Janine Sutphen's body was discovered floating in a Raleigh lake, investigators continue to find new evidence on computers seized from Robert Petrick's home that prosecutors say support their arguments that Petrick killed his wife.

The Google search was the latest in recently discovered evidence found on nearly a dozen computers seized from Petrick's home.

Last week, a forensic investigator discovered that Petrick allegedly researched lake levels, water currents, boat ramps and access about Falls Lake just four days before he reported Sutphen missing on Jan. 22, 2003.

Two of Sutphen's sons also testified Wednesday that they suspected their stepfather in their mother's death.

"I had to follow my gut and I did not feel safe or trust this man," said Robin Sutphen.

He told jurors that when he had not heard from his mother over a two-week period, he called Petrick and threatened to come to North Carolina to find out what was wrong.

The next day, Petrick reported Sutphen missing.

"It's been 2 years of listening to him avoid and tell lies and run spins," Robin Sutphen said.

During cross-examination, the strain in the Sutphen brothers' voices could be heard as they answered Petrick's questions. Both, however, looked the accused killer directly in the eyes.

"When you get up on the stand and look at the man who murdered your mother, you tend to want to confront him," Robin Sutphen told WRAL.

While the battle in the courtroom has been filled with tears, the brothers said they have also learned many good things about their mother.

"How she's touched everybody and how an amazing person she was and how much pride she had in her sons," Christopher Sutphen said. "So, we just go on living and maintaining and living up to what she'd expect of us -- the best."

Thursday will be a bittersweet day for the Sutphen brothers and their older half-brother. It would have been their mother's 60th birthday.