Okolona, Mississippi (CNN) -- For more than three months, Linda Smith has wondered how the man who police say was driving drunk and involved in a crash last year that killed her daughter could be pardoned for a previous felony drunken driving offense.
Former Mississippi Gov. Haley Barbour has said he didn't know that retired IRS investigator Harry Bostick had been arrested for a DUI months after the state's parole board recommended that Barbour grant him a full pardon. (Police have determined that while Bostick was driving under the influence, he was not at fault for the accident)
But e-mails recently obtained by CNN show that Barbour's office was aware of Bostick's October DUI arrest months before Barbour pardoned him along with more than 200 other convicted felons during his last days in office in January.
"They knew it, and they didn't stop it," said Smith, referring to the pardon. "Why didn't they do something?"
Smith spoke to CNN, overcome with emotion after reading the e-mails obtained through a public records request from Mississippi's Department of Archives and History.
The e-mails show that Amanda Jones, the governor's chief counsel, and Secretary of State Delbert Hosemann were told about the October car crash that killed Linda Smith's 18-year-old daughter, Charity Smith, just days after it happened.
Jones and Hosemann were even urged by a lawyer in the firm that represented Bostick not to issue the pardon, according to the e-mails. It is not known whether anyone communicated this information to Barbour. His spokeswoman would not comment on the e-mails, citing an ongoing case on executive pardon power that is before the state Supreme Court.
Barbour granted Bostick a full pardon in January for a felony drunken driving offense in March 2009. It was Bostick's third drunken driving arrest in a little more than year. The full pardon gave Bostick back the rights that were taken away as a felon, such as voting, but his two other DUI convictions remain on his record, according to the state attorney's office in Lafayette County.
Bostick was still going through a court-mandated drug rehab program when he applied for a pardon last summer. On September 30, the Mississippi Parole Board sent its review of Bostick's application to Barbour, recommending a full pardon in a 3-2 vote.
A week later, on October 7, Bostick was driving under the influence again, according to the Mississippi Highway Patrol. Charity Smith attempted to pull out onto a highway just outside Tupelo when Bostick's truck slammed into the side of her car.
Charity Smith was killed, and her older sister suffered serious injuries. Bostick was jailed for violating his probation from his previous DUI cases.
When he received the pardon in January, the convicted DUI felon still sat in an Oxford, Mississippi, jail cell, awaiting formal charges for his fourth drunken driving arrest.
A police investigation found that Bostick was under the influence of alcohol while driving but has determined that he was not at fault for the accident, according to the Mississippi Highway Patrol. Bostick has not been charged, and his case is expected to go before a grand jury, according to the state attorney's office.
If he is charged and convicted for the DUI offense, he will avoid the possibility of a stiffer sentence because it will be treated as his third DUI offense, instead of his fourth. However, he could go back to being a felon, and losing the rights restored to him under the pardon, with a third conviction.
Neither Bostick nor his lawyers have returned calls from CNN seeking comment.
Bostick's case offers a close look into the pardon process and the friendships and ties that often intersect with the political world. High-profile friends of the former federal investigator's, including lawyers and former U.S. attorneys, wrote letters to Barbour touting what they called Bostick's genuine lifestyle change.
The letters detail what friends described as Bostick's slide into alcoholism after the tragic death of his teenage son in a "freakish house fire" and his subsequent divorce, according to pardon and parole documents obtained by CNN.
"Harry Bostick has led a tragic life. A life that has now been turned around by a grace that is bigger than him," wrote retired U.S. Attorney Jim Greenlee. "He can now be a positive factor in many lives."
Another former federal prosecutor, Bob Whitwell, who is married to the sister of Greenlee's wife, also tried to help Bostick get his pardon.
"Bostick is a friend. He was a very good agent and worked a lot of drug cases and money laundering cases for me," Whitwell told CNN. "He was an outstanding officer. I knew him as a friend."
Whitwell, an attorney in the firm that has represented Bostick in his DUI cases, said he called Hosemann, his old law school friend, to help with the pardon, even though the secretary of state's office has no official authority to issue pardons. After the October crash that killed Charity Smith, Whitwell reached out to Hosemann in an October 11 e-mail, asking him to back off on the pardon.
"You asked me if he was straight and I gave you my word yes. For this I give you my sincere apology. I had no idea he had messed up. Therefore. Hold up on helping him. All of us are in shock. Sorry," Whitwell wrote.
He signed the letter, "Your friend bob."
Hosemann forwarded this e-mail to Barbour's chief counsel, Amanda Jones.
Her e-mail reply: "ok will do."
It's not known whether Jones spoke to Barbour about this before he issued Bostick's pardon. She did not return calls seeking comment. A spokeswoman for Hosemann said he never discussed the matter directly with Barbour.
Jones no longer works in the governor's office and is currently employed by the Mississippi law firm Butler Snow, the same firm that employs the former governor.
Whitwell said the October e-mail was the last communication he had about Bostick's pardon.
"I told Delbert that I wanted him to pull back that pardon. It must not have gotten to the governor if he got pardoned," he said.
Barbour has repeatedly said that as a Christian, he believes in forgiveness and second chances.
Wearing a pendant with her daughter's image emblazoned on it, Linda Smith said she sees the whole affair as the good ol' boy network at its worst.
"All I think about is my child every day, but I do know that certain people had to know, and they didn't do anything," she said with tears in her eyes.
"Haley Barbour had to have known. It's their job to tell him, so he had to have known," she said. "How do you do that?"
Watch Anderson Cooper 360° weeknights 8pm ET. For the latest from AC360° click here.