187 = Murder….not necessarily murder of a detective. Maybe the detective was involved in a murder in some other way.

Section 187 (often referenced in slang simply as 187) of the California Penal Code defines the crime of murder. The number is commonly pronounced by reading the digits separately as "one-eight-seven", or "one-eighty-seven", rather than "one hundred eighty-seven."

Murder trial started in October 2017 of Detective

http://abc7ny.com/murder-trial-begins-in-killing-of-nypd-detective-brian-moore/2552560/

Murdered detectives wife gives birth in mid-2017

https://www.telegraph.co.uk/news/2017/07/26/widow-murdered-nypd-detective-gives-birth-daughter-two-years/