VIDEO: St. Louis Chief Blames "Ferguson Effect" for Drop in Self-Initiated Policing

Numbers provided by the St. Louis Metropolitan Police Department show a downward trend, last year, in the numbers of self-initiated activity (S.I.A.)

The numbers show a high last year of more than 21,000 S.I.A. in March, now down by more than half to about 7,000 in December.

Chief Sam Dotson told Fox 2 News, "Police officers have an intuition. That intuition helps them to determine when to do self-initiated activity. It does reduce crime."

Though Dotson warns that the drop in S.I.A. doesn`t tell the whole story. During a period in 2013, he said crime also dropped along with S.I.A. He added, "That means police officers` activities were paying dividends. They were stopping the right people. They were in the neighborhoods experiencing crime. They were doing their jobs and doing it well."

One of the steepest drops in S.I.A. occurred after the August 2014 police shooting of Michael Brown in a St. Louis suburb. Another steep drop in S.I.A. occurred after the Grand Jury decision on Nov. 24. Dotson said criminals felt empowered, while officers felt hampered by what he calls the "Ferguson Effect."

S.I.A. numbers are climbing again, Dotson said.