Montgomery County’s top watchdog says he will step down from his post by the end of the year, punctuating his accusations that County Executive Ike Leggett’s administration interfered with some of his most damning investigations.

Inspector General Thomas Dagley’s surprising announcement comes more than two years before the end of his four-yearterm — and on the heels of claims that executive branch officials hampered his work and shared confidential names from his reports during investigations of their own.