Veteran public corruption investigator James Cabezas, who retired two years ago from Maryland’s Office of the State Prosecutor, has written a memoir of a four-decade career taking down corrupt government employees and politicians. This is The Baltimore Sun’s second peek into the plethora of public corruption history detailed in the book, “Eyes of Justice.”

In 1974, Baltimore police officers went on strike over failed contract talks with Mayor William Donald Schaefer. The nearly five-day walkout — the first by a big city police department in half a century at the time — resulted in looting and forced Gov. Marvin Mandel to send state police to patrol city streets.

Cabezas, a new officer disgruntled with the decision to strike, accepted an assignment that came straight from then-police commissioner Donald D. Pomerleau: join the Inspectional Services Division and spy on fellow cops who were union leaders. He reported back on one inconsequential meeting, noting that a joke had centered on tossing Pomerleau out a window.

Cabezas was surprised Pomerleau reacted by sending detectives to follow up on the joke as if it were a real threat, making it clear to union leaders that they had a mole among them.

But his surprise did not last long when news reports that year detailed how the commissioner had been using the I.S.D. to “spy on journalists and numerous black politicians,” the book states.

I.S.D., which reported directly to Pomerleau, opened files on 60 organizations, 99 men and 212 women, including politicians, public officials, clergymen, reporters and community activists. Black leaders were targeted specifically, including Congressman Parren J. Mitchell and City Councilwoman Victorine Q. Adams.

As Cabezas’ book put it, Pomerleau had “Hooverized” the department, referring to FBI Director J. Edgar Hoover, who had used his agents to conduct similar unlawful surveillance on civil rights leaders.

A special state Senate committee confirmed the spying and wiretapping in a 157-page report, but Schaefer reappointed Pomerleau, a decision approved by the General Assembly.

The News American newspaper’s investigation by reporters Michael Olesker and Joe Nawrozki “hit especially close to home” for Cabezas when it detailed “the infiltration of the police union during the strike.”

Cabezas avoided detection, a skill that would serve him well in his next assignment: faking his resignation from the police department to work undercover on the docks and along The Block to determine whether the Italian Mafia had come to Baltimore. No one knew of the assignment except for a select few in the department, where he was known to payroll only by a number: 232.

— Doug Donovan