TALLAHASSEE — Florida Department of Law Enforcement Commissioner Guy Tunnell, who has been criticized for the handling of an investigation into the death of a 14-year-old boy in Bay County, resigned Thursday.

The announcement by the governor's office followed a meeting in which Gov. Jeb Bush spent more than an hour with the parents of Martin Lee Anderson, who died after being beaten by boot camp guards.

Bush reportedly assured the parents that he was doing all he could to ensure a speedy investigation.

The meeting with Gina Jones and Robert Anderson effectively ended a student sit-in outside the governor's office that lasted about 34 hours. Organizers had pledged to remain in the Capitol until the release of a second medical examiner's report detailing Anderson's cause of death.

A single student, Kyle Washington of Florida A&M University, continued the protest Thursday night.

Earlier Thursday, Bush asked Hillsborough County State Attorney Mark Ober, who is overseeing the Anderson case, to widen the scope of his investigation and to consider making public the results of the second autopsy.

Tunnell could not be reached for comment after the governor's office announced his resignation. The announcement did not link the resignation to the boot camp investigation.

"I thank Guy for his service," Bush said in a statement. "He is a dedicated law enforcement officer who leaves behind an agency that is second to none."

Tunnell was Bay County's sheriff when Bush appointed him to lead the FDLE in August 2003. As sheriff, Tunnell started the Panama City juvenile boot camp where Anderson's January altercation with guards was caught on security videotape. Anderson died a day after being kicked and kneed by guards.

Ober removed the FDLE as an investigative agency in March because he had concerns about e-mails sent by Tunnell to Frank McKeithen, the current Bay County sheriff.

In the e-mails, Tunnell criticized those who questioned the effectiveness of the boot camp concept and discussed the FDLE's effort to withhold a video showing the guards' confrontation with the boy.

The meeting between Anderson's family and the governor was emotional, said Benjamin Crump, the family's attorney. He said Jones, Anderson's mother, alternated between grief and anger.

"She was very angry. She did not hold back with that. And the thing I appreciate is that Governor Bush did not shy away from that," he said.

Crump said Bush shared his frustration about the teen's death. He did not offer a formal apology but was "apologetic," Crump said.

The meeting left the family "encouraged but still cautious," he said.

"They'll feel a lot more trust from the system when arrests are made and people are held accountable for the death of their son," he said.

Bush contacted the Anderson family's attorney Wednesday, after the sit-in had begun, to schedule the meeting, his aides said. Bush said he thought it was appropriate to meet with the parents before a rally scheduled today.

"It shocked me that he wanted to talk to me... after almost four months that my baby's been gone, murdered, in a boot camp," Jones said before leaving the Capitol. "But we talked. We had a conversation about some things that he's going to start looking into now. I think he's getting on the right path now."

The weary group of about 35 students who spent the night outside Bush's office greeted Anderson's parents with a standing ovation at 4:30 p.m.

During the one-hour meeting, the students sang and continued an hourly reading of their grievances and demands, including the release of the second autopsy and the arrest of the seven boot camp guards involved in the beating. No one has been charged in the case.

The second autopsy, conducted by Hillsborough County Medical Examiner Vernard Adams, came after Bay County Medical Examiner Charles Siebert initially ruled that Anderson died of complications from the sickle cell anemia trait. Adams' autopsy has not been completed, but a medical examiner hired by the family has seen it and says it refutes Siebert's finding.

Crump praised the students for their activism and thanked them for calling attention to the family's plight.

He advised them to "get a good night's rest" to prepare for today's 9 a.m. rally and march with civil rights leaders Jesse Jackson, Al Sharpton and Greg Mathis.

"Because you all are bringing exposure to this issue, we can hopefully get to justice sooner rather than later," Crump said. "We look forward to seeing you bright and early for this rally."