Palo Alto's independent police auditors raised flags this week about the way the Police Department investigated an allegation that a detective threatened a suspect during an interrogation in 2012.

Auditors Michael Gennaco and Stephen Connolly affirmed the department's finding that the detective (who is not named in the report) acted within the department's policy and did not threaten the man during questioning. But the auditors also determined that a supervisor's interview of the detective during the internal investigation was "somewhat problematic."

The auditor's investigation was sparked by a complaint the department received in spring 2013 alleging misconduct during a criminal investigation the prior year. The complainant, who was incarcerated at the time, claimed that a Palo Alto detective "had made an inappropriate threat in the context of post-arrest interrogation," according to the audit.

The complainant, who was a suspect in several commercial burglaries, said in his letter that a Palo Alto officer made a "criminal threat" during an interrogation that involved two other detectives from a different agency. The complaint alleges that the officer told the man he would "die in prison" and "would never get out alive" unless he confessed.

In reviewing the tapes of the interview, Gennaco and the police department administration both concluded that harsh language was taken out of context and that no threats were in fact made. According to the audit, the statements in question occurred about four hours into the investigation. Prior to that point, the recording suggests that a department supervisor and the complainant have "good rapport" and that the officer took an approach that was "patient and solicitous."

Toward the end of the interview, a detective entered the room and began to confront the suspect with "harsh language and a dire assessment of his prospects," Gennaco's report states. The detective asserted that the suspect's family members and law enforcement officials "are going to make sure" that he dies in prison. In the context of the conversation, however, the statement was deemed by Gennaco to be not a threat but in fact a "harsh warning of the seriousness of the complainants situation."

The suspect, the audit notes, is in his 60s and said he had health issues, "which means a long prison sentence would indeed extend beyond his natural life span."

"Accordingly, the complainant's claimed interpretation of 'I am going to kill you' seems far less reasonable than something along the lines of 'Your sentence will be so long that you will never get out.' Nor does the 'real time' reaction of the complainant/suspect suggest that he felt rattled or unsafe as a result."

The audit found that the disputed actions of the detective during the questioning seem within the realm of permissible interrogation technique.

"While the critical moments are hard-edged to the point of slightly jarring, they are not so outrageous as to shock the conscience and do not lend themselves to the complainant's view of them," the report stated.

At the same time, Gennaco and Connolly also noted that the way the department interviewed the detective about the incident was problematic. The investigator's familiarity with the case and with the detective he was questioning "seem to affect the dynamic and interfere with both objectivity and thoroughness."

The supervisor was "candid about these factors," though the candor cuts both ways, the auditor wrote.

"It comes across as an honest reflection of a legitimate point of view about the case, and his transparency about it reflects an absence of guile or manipulation," Gennaco and Connolly wrote. "Nonetheless, as accurate as his personal assesment seems to be, it is less than ideal for various reasons. The most obvious of these is the undercurrent of bias it inherently suggests. Just as importantly, the pre-judging seems to preclude a focused, thorough discussion of the allegations from the subject detective's perspective."

The auditors noted that they have spoken to department leadership about this topic and "were pleased to note its concurrence regarding consistent professionalism in the interrogation context."