(AP Photo/Mark Lennihan)
(AP Photo/Mark Lennihan)

Police nationwide are on high alert following the shooting deaths of two New York City officers over the weekend.

FOX News Radio's Tonya J. Powers has more.

The deaths of NYPD officers Rafael Ramos and Wenjian Liu are being mourned nationwide. They were remembered Sunday at a candlelight vigil in Brooklyn...

(Singing from memorial) "Let it shine. Let it shine."

...at a makeshift memorial, there.

Ramos' cousin says he's still in shock.

(Ramos' cousin) "He was sweet. He didn't deserve like this to die...He just didn't."

Before Saturday's shooting in Brooklyn, police say Ismaaiyl Brinsley had vowed on social media to get revenge for the police-involved deaths of Eric Garner and Michael Brown.

He also shot his former girlfriend in Baltimore before going to New York. She's expected to be okay. Brinsley died after killing himself on a crowded subway platform minutes after the officers were shot.

In New York City, Tonya J. Powers, FOX News Radio.