Bill Matix and Mike Platt were best friends for more than a decade. They were known as devoted fathers and industrious businessmen. They had good military records, dating to the mid-1970s when they met as Army Rangers in the 101st Airborne Division in Fort Campbell, Ky.

The two men had no criminal records. Matix was a self-described born-again Christian who was featured last month in an article in Home Life, a magazine published by the Southern Baptist Convention.

People who knew Matix, 34, and Platt, 32, say that they seemed to be normal men who had put their lives back together following tragic events. Matix's first wife was brutally murdered at work Dec. 30, 1983, leaving behind a 3-month-old baby; and Platt's wife allegedly committed suicide on Christmas Eve 1984, leaving him with their three young children.

But police and FBI investigators say that this impression of Matix of Platt was misleading. On April 11, Matix and Platt died on a suburban Miami street in the bloodiest shootout in FBI history, leaving two agents dead and another five wounded.

Law enforcement sources say the men are suspects in half a dozen or more armored car and bank robberies, as well as attacks on target shooters at a rock pit just west of Miami. Police sources said vehicles taken from victims at the rock pit were later used by Matix and Platt as getaway cars.

In addition, police have reopened the cases on their dead wives, speculating that the Matix and Platt may have been involved. They are also looking into reports that Matix received $350,000 in insurance money after his wife's death.

"Your head would have to be on crooked to understand this one," said the Rev. Emit O. Ray, pastor of the Riverside Baptist Church where Matix attended services until about a year ago. Ray said his congregation has been stunned by the news and that members are puzzling over how they could have been fooled by Matix. "The average person doesn't think of church in the morning and murder in the afternoon."

The congregation includes a large number of local and federal law enforcement officers. Two deacons at Riverside are FBI agents. Ray said members of the close-knit church feel "foolish, used and taken in" by Matix.

Sgt. Tony Monheim of the Metro Dade Police Department, who had been investigating the robberies for several months, said he was stunned when he learned the identities of Matix and Platt. "When we started the investigation, we all said these guys are going to be neo-Nazis or escaped murders from some prison -- desperate people. Never in our wildest imagination did we figure they would be family types with no criminal record."

Miami FBI Agent Paul Miller, part of the team working to reconstruct the backgrounds of Matix and Platt, called them "two cold-blooded individuals willing to kill for money, willing to execute people . . . . "

According to what authorities have been able to piece together, Matix grew up in Dayton, Ohio. In the Home Life article, Matix said he left home about 1970, immediately after high school, "without direction from an alcoholic, divorced father" and joined the Marines.

In 1973, Matix said in the Home Life article, he decided to become a paratrooper.

Platt, meanwhile, had grown up in a Navy family, and his father, a chief petty officer, eventually retired in Homestead, Fla., west of Miami. After graduating from high school in Yuma, Ariz., in 1972, Platt got a two-year degree from Miami-Dade Community College and joined the Army Rangers. He was in the Army until 1979.

Platt moved to Miami and opened a small landscaping business -- called Blade Cutters -- with his brother, Tim.

Meanwhile, Matix had left the service, married and settled in Ohio with his wife, Patty, a laboratory technician. On Oct. 4, 1983, their daughter, Melissa, was born.

On the afternoon of Dec. 30, 1983, Patty Matix and a coworker were found murdered in their hospital laboratory. Police said Patty had been bound and gagged with white adhesive tape and stabbed 16 times in the chest and neck. Both women's wedding ring fingers had been cut off and were missing.

There has never been an indictment in the case, but Dayton, Ohio, police announced last week that they considered Platt and Matix potential suspects, and Dayton detectives flew to Miami to review evidence.

Matix told police that at the time of the murder he was home with his infant daughter.

The Columbus Dispatch has reported that Matix collected a $350,000 life insurance policy for his wife's death and also had filed a $3 million wrongful death suit Dec. 30 against the hospital.

The Dispatch also quoted police sources as saying Matix refused to take the lie detector test after his wife's slaying and was uncooperative with investigators.

After the murder, police say Matix and Melissa moved to Miami to be near Platt, and Matix joined in Platt's landscaping business.

According to Monheim, Matix and Platt "trusted each other totally" and were virtually inseparable -- except for the time that Matix was spending at the Riverside Baptist Church. He said Matix used the church "the same way some people would use a singles bar."

Ray said that Matix joined his church in August 1984, and appeared to be "looking for a woman." He said Matix attempted to date a number of young women in his congregation.

"He dated a few, and he showed an interest in others who didn't show an interest in him. He was aggressive in his pursuit of girls, and he introduced the idea of marriage very early in a relationship," Ray said.

"I hope beneath it all he really was a believer," Ray said. "Maybe if we'd known, we could have done a better job [with him]. I can't help but feel that somebody let somebody down."

One woman from Riverside who dated Matix told The Miami Herald that he seemed obsessed with finding a woman to take the place of his dead wife. "One of the first things he did was show me this clipping about her. He seemed like a normal person. The only thing was he dated a lot and he wanted to get married. He would date somebody a few times and right away want to make a commitment," she said.

Meanwhile, on Dec. 24, 1984, Platt's wife Regina died of a shotgun blast to the head. Police at the time ruled it a suicide.

But Metro-Dade Homicide Detective William Saladrigas said last week that the case was reopened after the shootout.

Saladrigas said that Platt, who was home at the time of the shooting, told police that he "was aware of a short affair between his wife and William Matix. He didn't appear to be upset about it, but he said he figured it would lead to a divorce. In fact, he said he was seeking a divorce at the time."

He said police initially believed the story because Regina Platt had once attempted suicide by taking an overdose of pills. But he added that "statistically and psychologically, it would be highly uncommon for a female" to commit suicide with a shotgun.

Police say that within several weeks Platt had married his second wife, Brenda. Platt rented out his small house, not far from the scene of the shootout, and moved with Brenda, her son and his three children to a luxury housing development.

Monheim, who participated in the search of Platt's home after the shootout, said he appeared to be living beyond his means. He described a television with a "gigantic screen," a $2,500 robot for the children and all-terrain vehicles. Among the vehicles registered to Platt, he said, were a Jaguar, a Jeep and a Chevrolet Blazer.

Meanwhile, Matix was in the process of acquiring a new wife. After a young woman at the Riverside Baptist Church broke off an engagement with him, Ray said Matix transferred last spring to the nearby Wayside Baptist Church in pursuit of another woman.

Not long afterward, Ray said, he was called by the pastor at Wayside who had been asked to marry the couple. "After counseling, he decided he wouldn't do the marriage, that they hadn't known each other very long and weren't ready for it. Then they eloped," Ray said. They were married last May.

According to divorce papers that have been filed in court, the marriage lasted a few weeks. At the time of Matix's death, he and his ex-wife were involved in a custody battle over their child, who was born several weeks ago.

His ex-wife wife, Christy Lou Matix, told the Associated Press, "I didn't understand why I left," she said. "It went against everything I believe in about family and children. Now I know: The Lord took me out of there . . . . I don't grieve for Bill. In fact, I guess the FBI did me a favor by taking him out. I grieve for the families of the agents who were slain."

Platt's brother, Tim, reached by telephone at Blade Cutters, refused to be interviewed. But Monheim said Tim Platt told police that his brother and Matix left the firm last summer, about the time Matix's second marriage was falling apart, to start their own landscaping business.

From that point on, police said they have not been able to discover any major source of legitimate income for the two men, other than the life insurance settlement on Matix's late wife.

Police are now reexamining many unsolved robberies and murders in connection with Matix and Platt. They won't say for sure when they believe the two began their crime spree, in which they often wore camouflage fatigues and coverered their faces with ski masks or military grease paint.

In at least one of the robberies they are thought to have committed, a guard was shot at point blank range several times, but survived.

Monheim said that FBI agent Benjamin P. Grogan, one of the two agents killed in the shootout, had been the first to figure out the link between the rock pit on the edge of the Everglades and the armored car robberies. He and Grogan spent the Saturday before the shootout going to nearby rock pits, questioning the target shooters.

Monheim said that Grogan had spent spare time cruising up and down South Dixie Highway, southwest of downtown Miami in the neighborhood where the robberies were occurring, looking for the missing cars.

It was one of those cars that Grogan spotted as he and other agents were staking out several banks in the area. They began a high speed chase down busy South Dixie Highway, calling for backup agents. The shootout finally took place on a modest residential street behind the Suniland shopping center, about a block off the busy highway.

The black Chevrolet Monte Carlo had been stolen from the rock pit March 12. Its owner, Jose Collazo, had been forced into a ditch and shot four times in the head, chest and arms. He pretended to be dead -- and survived.

Matix, with a Ruger Mini-14 automatic assault rifle, and Platt, with a 12-gauge shotgun, killed Grogan and Agent Jerry Dove, 30, and injured five other agents. As the two were trying to escape in an FBI vehicle, Agent Edmundo Mireles Jr., who was seriously injured, killed them.