EMBED >More News Videos Harris Co. DA Devon Anderson said 142 cases have been dismissed as a result of destroyed evidence

HARRIS COUNTY (KTRK) -- As the scandal over the destruction of evidence continues to unfold, Harris County Precinct 4 Constable Mark Herman says he would welcome any outside agency to investigate his office."We would definitely have no problem with anyone investigating our office," Constable Herman said. "All I ask, is that whoever comes in, if they come in, that they stay out of our way and continue to do our jobs."Herman's office recently fired veteran Deputy Constable Christopher Hess over allegedly improper destruction of thousands of pieces of evidence. Herman says he is convinced Hess was the only one operating improperly."This guy has been here, he's a 10-year police officer," Herman said. "He knew from right and wrong. Again, whether it is was intentional, negligence or accidental, we can't tolerate it in this business. He has caused a lot of people a lot of grief, including the people arrested."More than 140 criminal cases in Harris County have been dismissed because evidence needed for trial was destroyed, according to District Attorney Devon Anderson. Last week, Anderson said more cases in Precinct 4 are under review. She said she asked prosecutors in those cases to review each case and find out if evidence is missing. The destruction of 21,000 pieces of evidence going back to 2007 is being scrutinized.The Harris County District Attorney's office says it is already investigating whether what happened in Precinct 4 was a crime. However, defense attorney Tyler Flood, the current president of the Harris County Criminal Lawyers Association (HCCLA), says that's not good enough."Because the DA's office is investigating Precinct 4, but nobody is investigating the DA's office other than the DA's office," said Flood.HCCLA has sent a letter to federal authorities, asking the U.S. Attorney's office to step in. That letter is the second to also includes a request to immediately de-certify Precinct 4 of its law enforcement abilities as the criminal investigation continues. Criminal defense attorney Paul Morgan sent his own letter to state, county and city officials. Constable Mark Herman responded to the demand in a news conference."That's ludicrous. If we have done something wrong, we handled the problem. That employee was fired," Herman added.