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A standoff in rural Alabama entered a fourth day Friday as police surrounded an underground bunker where a retired truck driver was holding a 5-year-old hostage he grabbed off a school bus after shooting the driver dead.

Police say the suspect, identified by neighbors as Jimmy Lee Dykes, built the bunker himself and has been known to stay in it for days. The bunker is six by eight feet and is four feet underground. Police have been communicating with the suspect through a 60-foot PVC pipe.

Speaking into the pipe, hostage negotiators tried again Thursday to talk the 65-year-old retired truck driver into freeing the boy. One local official said the child had been crying for his parents.

The normally quiet red clay road leading to the bunker was teeming Friday with more than a dozen police cars and trucks, a fire truck, a helicopter, officers from multiple agencies and news media near Midland City, population 2,300.

Police vehicles have come and gone steadily for hours from the command post, a small church taken over for that use.

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Early Friday, activity picked up when a team in military-style uniforms, many toting weapons, got out of a big van in the pre-dawn chill and moved into a staging area. One appeared to be dog handler.

But after a chilly night, the activity of law enforcement appeared to slow approaching dawn though a mobile command center remained lit with bright lights. Overhead, a small aircraft with blinking lights flew wide circles high above the man's property early Friday. An ambulance was parked nearby.

The boy being held was watching TV and getting medication sent from home, according to state Rep. Steve Clouse, who met with authorities and visited the boy's family. Clouse said the bunker had food and electricity.

Authorities lowered medicine into the bunker for the boy after his captor agreed to it, Clouse said.

Dykes was known around the neighborhood as a menacing figure who once beat a dog to death with a lead pipe, threatened to shoot children for setting foot on his property and patrolled his yard at night with a flashlight and a shotgun.

Neighbors describe Dykes as being "anti-government" and said he was "a long time concern" in the community, WSFA.com reported. Police Chief James Arrington says the kidnapping and murder could be a hate crime because of Dykes' previous threats. Court records show he was due in court Wednesday morning to face menacing charges, according to the station.

Authorities say the gunman boarded a stopped school bus Tuesday afternoon and demanded two boys between 6 and 8 years old. When the driver tried to block his way, the gunman shot him several times and took a 5-year-old boy off the bus.

Dykes had been scheduled to appear in court Wednesday to face a charge of menacing some neighbors with a gun as they drove by his house weeks ago.

Homes on the road had been evacuated earlier after authorities found what they believed to be a bomb on the property. SWAT teams took up positions around the gunman's property and police negotiators tried to win the kindergartner's safe release.

The situation remained unchanged for hours as negotiators talked to the suspect, Alabama State Trooper Charles Dysart told a news conference late Wednesday. Earlier in the day, Sheriff Wally Olson said that authorities had "no reason to believe that the child has been harmed."

Local TV station WDHN obtained a police dispatch recording of the moment officers first arrived at the site. On it, the officers are heard saying that they were trying to communicate with Dykes through a PVC pipe leading into the shelter.

Authorities gave no details of the standoff, and it was unclear if Dykes made any demands from the bunker, which some officials described as being like the underground tornado shelters some homes have in their yards.

"As far as we know, there is no relation at all. He just wanted a child for a hostage situation," said Michael Senn, a pastor who helped comfort other traumatized children after the attack.

The bus driver, Charles Albert Poland Jr., 66, was hailed by locals as a hero who gave his life to protect the 21 students aboard the bus. Authorities say most of the students scrambled to the back of the bus when the gunman boarded.

Neighbors described a number of run-ins with Dykes in the time since he moved to this small town near the Georgia and Florida borders, in a region known for peanut farming. Dykes had been scheduled to appear in court to answer charges he shot at his neighbors in a dispute last month over a speed bump.

In that dispute, neighbor Claudia Davis said he yelled and fired shots at her, her son and her baby grandson over damage Dykes claimed their pickup truck did to a makeshift speed bump in the dirt road. No one was hurt.

Mike and Patricia Smith, who live across the street from Dykes and whose two children were on the bus, said their youngsters had a run-in with him about 10 months ago.

"My bulldogs got loose and went over there," Patricia Smith said. "The children went to get them. He threatened to shoot them if they came back."

"He's very paranoid," her husband said. "He goes around in his yard at night with a flashlight and shotgun."

Another neighbor, Ronda Wilbur, said Dykes beat her 120-pound dog with a lead pipe for coming onto his side of the dirt road. The dog died a week later.

"He said his only regret was he didn't beat him to death all the way," Wilbur said. "If a man can kill a dog, and beat it with a lead pipe and brag about it, it's nothing until it's going to be people."

Fox News' Elizabeth Prann and The Associated Press contributed to this report.

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