The arrests stem from a 15-month investigation that included wiretaps on 15 telephones, physical surveillance and controlled purchases and seizures of cocaine and heroin.

WSJ: About 100 charged in New England drug raids

"Their role is to utilize their special training to conduct a more comprehensive investigation, employing a variety of techniques in order to establish speed, analyze skid marks and other physical characteristics of the accident scene, " said John Cassidy, executive officer of the Transportation Bureau of the NYPD, at a City Council hearing in February.

CNN: Bicycle injuries: Is the right-of-way fight getting ugly?