September 26, 2012 at 2:27 AM EST - Updated June 28 at 7:55 AM
DELRAY BEACH, FL (WFLX) David Chin was a Delray Beach police officer whose primary job was getting drugs off our streets.
Last month though, the state attorney's office let twenty suspects know they were being let off the hook because Chin was facing charges for allegedly lying about a confidential informant he had been pursuing for a date.
As a member of the street narcotics unit, Chin specialized in surveillance and working with confidential informants.
He built cases against suspects for firearms possession, drug trafficking and assaulting a policeman.
Ann Stacey-Wright of the Southwest Neighborhood Association says she'd seen him at anti-violence meetings.
"He seemed like he was productive and he was concerned with the neighborhoods," said Wright.
But twenty of his cases have come tumbling down.
The problems stem from the case against drug and firearms suspect Henry Rauche, which investigators say Chin built in June of last year with the help of confidential informant Natalie Jerue.
Investigators say he'd been trying to get charges dropped against Jerue after trying to date her and that he claimed she'd provided crucial information against Rauche.
On August 15, the state attorney charged Chin with perjury and official misconduct.
"The last thing we need is a corrupt officer," said Wright.
After Chin was charged, the state attorney dropped cases against Rauche and nineteen others, saying Chin could no longer be called to testify as a key witness.
Three of the suspects are still in jail, held on other charges. But seventeen are out, charges dropped. Many have home addresses on Delray's west side.
City commissioner Adam Frankel says this hurts the city's fight against crime.
"It's a huge setback, no question about it, " said Frankel.
Commissioner Frankel defended the department, saying he believed wrongdoing was limited to Chin, who is on unpaid administrative leave.
"It appears to me, without knowing all the facts, that they did an investigation, they found a bad apple, and they acted appropriately and swiftly," said Frankel.
Delray Beach Police say they will not make any comments about Officer Chin or any of his cases until the Internal Affairs investigation is complete.