[A]t least 37 people in the District and Maryland  have been killed since 2004 for cooperating with law enforcement or out of fear that they might, according to a Washington Post examination of hundreds of police and court records. . . . .
The Post’s review found that among those killed for cooperating with authorities or out of fear that they might:
●At least 19 didn’t receive protection, including a confidential informant working for the Drug Enforcement Administration who was lured to a home by a drug dealer’s girlfriend and then fatally shot by the dealer.
●At least five were killed after defense attorneys learned their names or other identifying information and told their clients. In one case, a lawyer tipped off a defendant that prosecutors wanted to interview the witness. Six days later, the witness was found dead.
●Nine were offered protection but declined, including a 38-year-old Baltimore County man who was unaware of the long criminal history — including murder, attempted murder and firearms charges — of the man he was scheduled to testify against.
●At least five were slain after they were relocated but returned to their old neighborhoods.
●In at least four cases, charges against a defendant were dropped after the witness was killed.