A half-inch of rain also fell in Memphis Nov. 19, the day before homicide detectives took over.

According to James Burke, a state-certified private investigator in Boston, any precipitation could have compromised forensic evidence on the bridge and its railings. Wiley would have had to climb over the bridge’s high railings in order to jump off, MPD spokesperson Richard True said.

Within days of taking over the case, homicide detectives also scanned surveillance videos at local stores for evidence of Wiley’s activity after he left the hotel, put up posters with Wiley’s picture and interviewed Peabody employees, conference attendees and others in the area around midnight on Nov. 15.

According to True, the department has assigned three full-time detectives to work exclusively on the Wiley case and can add more as needed.

Able stressed that Wiley is still being investigated as a missing person, not a suicide.

But the MPD officer said, “We probably know where he is right now, but no one wants to believe us. Ninety-nine percent of abandoned cars we find, [the drivers] go in the river.”

Able, who took over responsibility as the MPD spokesperson on the Wiley case yesterday, declined to comment on any of the evidence Susan Wiley says Shemwell discussed with her.

—Daniel K. Rosenheck can be reached at rosenhec@fas.harvard.edu.

—Elisabeth S. Theodore can be reached at theodore@fas.harvard.edu.