The most pressing question about the creep who has slashed the buttocks of nine young women at Fairfax shopping centers this year is: Why haven’t they caught him?

The police know what he looks like. The culprit has made surprisingly little effort to conceal his face, so detectives have numerous photos of a suspect from store surveillance cameras.

The public is well aware that he’s out there and has provided the police with plenty of tips. At Fair Oaks Mall in Fairfax, where five of the attacks took place, every person I interviewed Wednesday had heard of the assaults.

“It makes me a little bit nervous to come here by myself. I definitely look around before I bend down to pick up clothing,” shopper Alysia Smith, 22, said.

Susie Escobar, 25, who works at the mall in the state Department of Motor Vehicles office, said the attacks have “terrified” her. She’s staying out of department stores, where many of the assaults occurred, and expressed surprise that the slasher was still at large.

“They have so many images of him, and he’s done so many attacks. How can you not catch him?” she said.

It’s not for lack of trying. In a large, affluent county like Fairfax — with a well-funded police department and a low crime rate — a high-profile serial assailant who’s wantonly targeting the public is sure to get loads of attention.

The department set up a task force to go after the guy after realizing in late July that a slashing in February was part of a pattern rather than an isolated case. It has a minimum of 12 officers and other staff working on the case full time.

That hasn’t been enough so far, partly because of the large volume of people to monitor.

“If you look at the daytime population of Fairfax County, between residents and businesses, you have perhaps 2 million people traversing the county. Trying to find the suspect is like looking for a needle in a haystack,” said Lt. Col. Ed Roessler, the county’s deputy chief of police for patrol.

Moreover, the same publicity that yields crucial leads also alerts the weirdo that he’s being watched. It might have pushed him into hiding. No slashings have been reported since police went public with the story in late July after realizing there was a pattern of attacks stretching back months.

Still, despite the difficulties, I predict they’ll catch him. For one thing, the suspect’s behavior so far suggests he isn’t particularly worried about being arrested. So there’s a good chance he won’t lie low permanently.

Robyn Diehl McDougle, a criminal justice professor at Virginia Commonwealth University in Richmond, said that reports of the case suggest the slasher is part of “a very small population” of criminals who mostly ignore the possibility of apprehension.

She noted that the slasher has struck during the day in public places. He hasn’t robbed his victims but wounds them with a box cutter or razor — enough to draw blood but not require stitches.

“The way he’s going about this is, he’s paying very little attention to trying not to call attention to himself,” McDougle said. “In sharp force trauma, you’re getting very close to your victim. That increases your chance of getting caught.”

Moreover, she said, it’s likely he won’t be able to resist the urge to attack again. This type of criminal often suffers from some kind of mental illness involving powerful compulsions, she said. He might even welcome the increased risk now that his photo is in the news.

“His driving force might be that he likes the attention,” McDougle said.

The public’s interest is another factor working in favor of the police. People are clearly on edge about the case and are creating a lot of work for detectives with all the leads they’re providing. A citizen’s tip led to an arrest in a series of burglaries last year, and police think the same is likely to happen here.

The public has “more eyes and ears in these retail districts than we have. Usually it’s an alert citizen who helps solve it,” Roessler said.

In the meantime, shoppers are taking precautions. Carlie Robbins, 18, who was buying clothes for school with her younger sister, said neither would have come by herself.

“It’s kind of scary. All the victims have been by themselves, so we’re sticking close together,” Robbins said.

I discuss local issues at 8:51 a.m. Friday on WAMU (88.5 FM).