Live updates: Michigan school shooting and search for Ethan Crumbley's parents

Oakland County, Michigan, sheriff Michael Bouchard said he did not know that charges were going to be filed against James and Jennifer Crumbley until he heard about it in the media.

“We didn't know that charges were issued until we started hearing from the press that there was going to be a press conference about charges,” he said in an interview with Hallie Jackson on MSNBC Friday.

“If we knew, if we knew that there was a high likelihood of charges, especially serious charges, you know, obviously, that's where you begin to differentiate how many resources you devote to it,” he said. “Because again, we've got a ton of our folks very much involved in the investigation of the actual shooting. So, we would have had to pull people off of that investigation to begin working on a surveillance which we would have done if there was an indication that serious you know, felonious charges may be forthcoming.”

When Jackson asked Bouchard if he was frustrated that he was not given notice about the charges, he said, “That’s an understatement.”

He continued, “We're working on a relationship. The prosecutor is new. And we're doing our best to make sure that these kinds of things and communication happens in a more fluid way. That's the best I can tell you,” Bouchard said.

The Crumbleys — the parents of the 15-year-old student accused of killing four people during a shooting at Oxford High School in Oxford, Michigan — face involuntary manslaughter charges in the Tuesday shooting. Their son is charged with murder, terrorism and other charges in the shooting.

James Crumbley bought the semiautomatic handgun recovered in the attack four days before the shooting, the prosecutor said. She called the parents' actions "egregious."