Much has changed in the criminal- justice world since Joseph A. Giacobbe became a federal probation officer in New York City in 1976.

In those days, a telephone was the closest thing that Giacobbe had to high-tech equipment as he tried to keep track of accused mobsters and drug dealers who were awaiting trial in the Big Apple.

Today, probation officers use computers, electronic ankle monitors and global positioning systems to keep watch on criminal suspects.

“The job is a lot more complicated today,” Giacobbe said. “But now, the probation officer has more tools than ever to help [him] do the job.”

Giacobbe, 56, recently put in his last day of work after 19 years as the chief probation officer for the federal courts of Western New York.

Widely respected by judges, police and defense attorneys, Giacobbe was the longest-serving chief probation officer among those in 94 federal court districts throughout the United States.

Giacobbe transferred from New York City to Buffalo in 1981. Ten years later, at age 38, he became the youngest chief probation officer in the nation’s federal court districts. In 2001, he received a national leadership award from the federal court system, calling him the best chief probation officer in the nation.

“Joe did an excellent job. His work gave him national prominence in his field,” said William M. Skretny, the chief federal judge for the district. “The people in Joe’s office always treated criminal defendants with the utmost respect, and that’s what I believe Joe will be remembered for.”

Their work is rarely publicized, but probation officers serve an important role in the federal courts, from the pretrial stage until the person is released from prison.

When a person is charged with a federal crime, probation officers examine the individual’s criminal record, background and the nature of the latest charges. The probation officer writes a report that helps judges determine whether the person can safely be released on bail while his or her case awaits trial.

If the person is convicted and sentenced, probation officers then write a detailed report to help the judges determine what sentence the person should receive under advisory sentencing guidelines.

If the person is placed on probation or is under court supervision after serving a prison sentence, the probation officer checks in with the individual to make sure he or she stays out of trouble.

The job may involve making home visits in the roughest of neighborhoods or making sure the individual takes part in drug testing or mental health counseling.

The federal probation offices in Buffalo and Rochester have more than 75 employees who supervise about 2,000 defendants and ex-offenders.

When people are charged with federal crimes in Buffalo, judges release them on bail — rather than jailing them — about 74 percent of the time. According to Giacobbe, that number is well above the national average.

It costs taxpayers far more to keep defendants in jail than it does to have them out on bail or in home confinement, Giacobbe said.

“Jail costs the taxpayer about $100 a day, and home confinement costs about $5 a day,” Giacobbe said. “My philosophy has always been, ‘The person is innocent until proven guilty.’ If we can arrange something to allow them to stay out of jail while they wait for trial, that is preferable.”

An Amherst resident, Giacobbe is married with two sons and a daughter. In retirement, he plans to play a lot of golf and possibly pursue some teaching and consulting work.

Giacobbe was thrilled when federal judges chose his deputy for the past eight years, Anthony M. San Giacomo, to replace him.

During Giacobbe’s final day on the job, federal judges held an emotional farewell ceremony for him and presented him a plaque of appreciation.

“I appreciated the plaque and the kind words, but the time I really got choked up was when they announced Tony would succeed me,” Giacobbe said. “He was the person I recommended, and that meant a lot to me.”