"For any college coach, the thing that always worries me, is what I don't know," Krzyzewski said recently. "Somebody can say, well, you're supposed to know everything. You can't know everything. You can know as much as possible while they're here. But it's impossible for you to know what went on before they got here."
Every coach has his own process for vetting potential recruits and it almost always involves trust.
"The element of trust still has to be there," Krzyzewski said in October. "Most of the time that trust pays great dividends, but every once in a while somebody might not tell you everything."
Krzyzewski said Duke's compliance staff plays an important role.
"If you find out that there was an incident then you would take the proper steps with the NCAA to talk about that before a kid would ever play for you," he said. "That's been done forever, for my 38 years here."
That was the case with Duke freshman star Marvin Bagley III, who announced last month that he will enter June's NBA draft.
Bagley was the subject of a report last month in The (Portland) Oregonian that detailed connections between his family and Oregon-based Nike through grassroots basketball programs in Arizona and California. The report touched on the family's finances as well as Bagley's high school academics. It illustrated how complicated and potentially troublesome a young basketball player's history can become.
A Duke official told The News & Observer earlier this month that the school and the NCAA had cleared Bagley to play last summer.
"We and the NCAA evaluated his amateur status and determined him to be eligible," Todd Mesibov, Duke's compliance director, said about Bagley in a statement.
As it normally does with elite basketball recruits, the NCAA Eligibility Center examined the Bagley family's finances before approving Bagley to play college basketball at Duke this season, according to sources close to Duke's basketball program.
But the recruit vetting process starts with coaches.
N.C. State head coach Kevin Keatts says he tries to get to know players and their families as early as the ninth grade.
He said it's important that everybody on the college staff gets involved with high school coaches. "Being a former high school coach or prep school coach, I thought it was important to be able to talk to some of the college coaches," he said in October.
"I think you've got to start early. I think relationship-building, you've got to find the guys that fit the culture of the school. That's academically, socially and then basketball wise."
Keatts said parents need to have a central role in recruiting and the way to do that is to educate them about the process.
"And that doesn't allow other people to be involved in your recruiting," Keatts said.
UNC's Williams said in October he talks to as many people at a player's high school as possible, from guidance counselors and teachers to custodians and principals.
When asked what he does to ensure players he recruits are not breaking the rules with agents, Williams said information is key.
"We tell them this is the way things are supposed to be done and that somebody can affect your eligibility when you get here," Williams said. "I think we even have something that they are supposed to sign saying they haven't dealt with any agents. I just think its (sports agents) a bad profession. They want part of your money."
Williams added that former UNC coach Dean Smith brought athletes in and interviewed their families. Williams has adopted that practice.
"I trust the kids a lot," Williams said. "There's two pieces of advice I give every one of them: 'Don't take anything, except from your parents and us. I'm not going to give you anything illegal and your parents can give you anything they want. If you follow that rule there's no problem.'"
Senior guard Joel Berry said if an agent contacts them in college, players are instructed to email the coaching staff and let them know who it is.
"When we go out in the public we don't have any safety around and we don't know what's the person's intentions that's coming up to you," Berry said. "That's what's so hard about being a well-known athlete in whatever town you're in ... It's hard to distinguish from a fan and somebody trying to get attached to you," Berry said.
Seth Greenberg, the former Virginia Tech head coach and current ESPN college basketball analyst, said he thinks coaches do enough to check out recruits, but agrees with Krzyzewski that it's hard to know everything.
"When you recruit a player, you recruit the circle of influence," Greenberg said. "But it's like anything else. You can't hold their hands 24/7. Their parents don't know where they are 24/7 and you don't know what their parents are doing."
There is plenty for coaches to be concerned about.
In September, the FBI announced that it had arrested 10 people, including assistant coaches, agents, advisers and AAU coaches in connection with fraud and corruption schemes. At least six college basketball programs and possibly many more were said to be involved in two different efforts.
One scheme involved paying players as much as $150,000 in exchange for their commitment to certain adidas-sponsored universities. The other involved coaches receiving payments to steer players to agents.
Players recruited by North Carolina Triangle universities were linked to the scandal, including Brian Bowen, who was also recruited by N.C. State, Nassir Little, who eventually signed with UNC., and apparently, Smith.
The documents released on Tuesday don't name any N.C. State players or coaches. But details in them make it clear the player involved is Smith, who played for the Wolfpack in the 2016-17 season before entering the NBA Draft. Neither Smith and his family nor any N.C. State coaches have been indicted in the case.
According to the FBI documents, former adidas employee James Gatto conspired to funnel $40,000 to the father of a Wolfpack recruit to secure his son's commitment to N.C. State. The FBI pointed out that N.C. State was under contract with adidas at the time.
The indictment points out that the athlete committed to N.C. State in September 2015 only to begin having second thoughts. At that time, Gatto agreed to funnel $40,000 through a N.C. State coach, who is not named in the indictment, to Smith's father.
The coaches who recruited and coached Smith at N.C. State, including head coach Mark Gottfried, were fired in March 2017.
Attempts to reach Gottfried, who was hired by Cal State-Northridge as its head basketball coach last month, and former N.C. State assistant coach Orlando Early for comment have been unsuccessful. Smith told the Dallas Morning News on Wednesday that he did not want to talk about the FBI investigation but was not worried about it.
In a statement released Wednesday, N.C. State spokesman Fred Demarest said the school contacted Gottfried and his former assistant coaches about the FBI's allegations last year.
"NC State's Office of General Counsel and Athletics' Compliance staff contacted former basketball coaches asking whether they had any knowledge of or involvement in any activity related to the allegations coming from the U.S. Attorney's Office," Demarest said in the statement. "Former staff questioned stated they had neither any knowledge nor involvement."
Bowen once had N.C. State high on his list of schools to attend. But after Gottfried was fired last year, Bowen dropped the Wolfpack from his list. FBI documents state that Dawkins and others offered to funnel Bowen's family $100,000 in order to get him to sign with Louisville. As part of the fallout, Louisville coach Rick Pitino and the school's athletic director, Tom Jurich, were both fired. Bowen is now with South Carolina.
At UNC, Williams has said he does not believe Little was involved in any wrongdoing. The FBI's documents described Little's AAU coach, Jonathan Brad Augustine, as a facilitator of a deal to get him to sign with Miami. It doesn't describe Little or his family as having discussions about any deal.
Little and his father denied involvement in the case, and both signed sworn affidavits. Williams said he trusts what Little and his father have said.
Krzyzewski has suggested solutions for how the NCAA can prevent issues that occur before a player enrolls in college.
"It might for, (future coaches) when they go into a home, there's an agent there," Krzyzewski said. "Which may not be bad. Because at least they would be getting expert advice that they chose. They wouldn't have to go around and say I know this guy."
"Maybe there's a way of checking their credentials, so the NCAA could provide guidance to freshmen, sophomores, juniors and seniors, that the agents would have to register and you would have their profiles. Things like that, like let's just get ahead of the game."