On the fifth day into the the investigation into the disappearance of a 6-year-old Tucson girl, Police Chief Roberto Villaseñor today defended the pace of progress in the case.

“It’s not like TV,” he told a reporter who asked if he was concerned about the number of days that have passed since Isabel Mercedes Celis was first reported missing Saturday morning.

“Forensic work takes time. Investigative work takes time,” Villaseñor said at a news briefing this afternoon. “We’re trying to do the best we can with limited information.”

He said he is proud of the effort put forth by his department and other agencies helping find Isabel.

Villaseñor updated reporters on the investigation two hours after Isabel’s parents pleaded for their daughter’s safe return in a news conference carried live on TV.

There have been more than 300 leads in the case, Villaseñor said today, noting that they are not coming as often as they had earlier in the week. He said the slowdown in new tips might have played a role in the parents’ decision to have a news conference earlier today.

Villaseñor said no one was been eliminated as a suspect in the case.

He also said investigators have searched washes, abandoned homes and desert areas.

Still, Villaseñor said he is working under the assumption Isabel is alive.

About $20,000 has been raised in private donations for a reward in the case, though officials say more than $30,000 has been pledged.

Villaseñor said FBI profilers brought to Tucson this week to help with the probe had not yet interviewed the parents. He said it is up to that agency to decide when that will occur.