Two Texas police officers frequently made homeless people and prostitutes sign blank tickets so they could later fill them out with whatever offenses they chose, according to a Dallas Police Department investigation.

Dallas Police Chief David Kunkle said investigators concluded the two officers used the blank tickets as a law-enforcement tool against habitual offenders. If those offenders always had unpaid tickets, then officers could obtain arrest warrants and take people into custody at any time, Kunkle said.

"It's hard for me to understand any circumstances where that would be appropriate," Kunkle told The Dallas Morning News. "It certainly violates fundamental fairness if people don't have the opportunity to know what they're being charged with or get proper notification."

A formerly homeless man interviewed by investigators said he was a frequent target.

"They had me signing blank tickets every time they seen me," said the man, R.B. Barton.

The two accused officers are Senior Cpl. Timothy Stecker and Senior Cpl. Jeffrey Nelson. Stecker had previously been cleared of charges related to his ticket writing but was placed on restricted duty Friday. Nelson is already on restricted duty for a pattern of misconduct related to ticket writing, police said.

They are likely to face disciplinary action; a hearing on their cases is scheduled for Tuesday.

An attorney for the two men said they are good officers who have been treated unfairly by the department's investigators.

"The way this investigation has been conducted, the length of time that it has taken the department, and just the way that this investigation was initiated and continues to be modified continually by the department has been very unfair to the officers," said the attorney, Haakon Donnelly.