Suffolk County's police commissioner says crime is down this year in Brentwood, but a number of recent killings have residents concerned.

Suffolk Police Commissioner Timothy Sini says a recent police crackdown in the area is yielding positive results.

He says the Suffolk County Police Department has made 30 arrests of suspected MS-13 gang members since the initiative began on Sept. 13. Police are also working with federal prosecutors to put more behind bars.

"We now have five known, violent MS-13 gang members in federal custody with federal RICO charges," Sini says.

Sini says property crime over the last 30 days is down 34.4 percent. Violent crime, including gang-related violence, is down 75 percent within the last 28 days compared to the same time last year.

But residents are skeptical, especially in the wake of several recent killings in the area.

"These are tragic homicides, and we're doing everything we can to get to the bottom of these crimes," Sini says.

The commissioner says community members play a huge role in solving such crimes. Anyone with tips can call Crime Stoppers at 1-800-222-TIPS.