Entenza first downplayed his investigation into Hatch. He says in March of last year, he asked for basic public information that any citizen could get, and his campaign manager released the result to the press -- a box of routine public documents on the attorney general's office.
Two hours later, Entenza said he had just discovered that Chicago-based Gragert Research also asked a local sheriff about Hatch's past parking record.
"I was just looking to get some basic public documents ... They decided that they would get these extra public documents. And it is deeply embarrassing to me, and I take responsibility for the fact that it happened," said Entenza.
Gragert Research is known as a company that does opposition research on candidates. The head of the firm, Dennis Gragert, wasn't available for an interview. He said in a statement that his firm collected a larger scope of public documents than Entenza requested, and only delivered to Entenza the public records provided by the attorney general's office.
Entenza says he turned over everything he got from Gragert Research to the Capitol press corps. The box he released mostly contains annual reports on the attorney general's office, budget information and court filings.
Entenza says he didn't know about the parking ticket request until someone showed it to him on the blog MinnesotaDemocratsExposed. He says he doesn't think his campaign manager told him about it a year ago.
It is deeply embarrassing to me, and I take responsibility for the fact that it happened.
Entenza says when Hatch found out about Entenza's research last year, Hatch told Entenza that he should have simply asked for the information instead of using the Chicago firm.
"In retrospect, the right thing for me to do would have been to go into Mike's office and ask to sit down and talk to his budget person and what have you," said Entenza. "I thought it would be easier just to get some copies of reports. Apparently it would have been better to do it differently. But such is life."
Entenza says he hired Gragert Research to do a data request because he hadn't worked for the AG's office for a decade and wanted to get up to speed on the inner workings of the office. He says he wasn't trying to dig up dirt on Hatch, who at that point hadn't announced whether he was running for governor or another term as attorney general.
Republicans have pounced on the tiff between two of the state's top Democrats. Republican attorney general candidate Jeff Johnson says Entenza's stories don't add up.
"It's an issue of character," says Johnson. "I've heard a lot of people questioning, what's the real reasoning behind this, and why didn't he tell the truth at first, and is he telling the truth now?"
Johnson has also questioned whether Entenza could oversee the state's health care industry as attorney general, when Entenza's wife Lois Quam is a top executive with UnitedHealth Group. Quam is the CEO of a company subsidiary.
Entenza says he would turn over decisions on cases involving UnitedHealth Group to top attorneys in the office, and he challenged Johnson to release his client list as an attorney in private practice.
Hatch has laid low since the story broke. But he said in a statement that after being investigated by big HMOs like HealthPartners and Allina, any investigation of him by a public official would be "of absolutely no concern" to him.