In Dallas, five police officers were killed by a gunman angry with law enforcement for killing black men. In Missouri, a family mourns the loss of 18-year-old Michael Brown, an unarmed black student killed in a fatal police shooting.

With tensions high between minorities and police departments across the nation, local leaders will host National Night Out activities Tuesday to bolster ties between law enforcement leaders and the communities they serve. The annual event comes at a time when lawmakers and social justice activists are calling for police reforms amid high rates of police killings and a growing trend of brutal death by police videos being shared on social media.  

In California, communities including Anaheim, Costa Mesa, Laguna Beach, San Francisco and Yucca Valley will hold celebrations to honor National Night out. In New York, there will be block parties and concerts in New York City, Rochester, White Plains and other cities. A full list of events can be found here. Roughly 38 million people in 16,000 communities are expected to participate. 

"National Night Out’s objectives include refining the nationwide crime prevention campaign, documenting successful crime prevention strategies, expanding Project 365, disseminating information about successful community-based strategies, providing technical assistance on crime prevention program development, and developing the National Night Out Web site," according to the site.

Law enforcement officials killed nearly 1,000 people last year, according to a Washington Post investigation. About 34 U.S. law enforcement officers have died from shootings in 2016, up 79 percent from last year, according to the National Law Enforcement Officers Memorial Fund, which keeps data on officers killed on the job.

After a man opened fire on Dallas police in July, President Barack Obama urged law enforcement officials to build trust in the communities they served. He also celebrated police officers for keeping communities safe. 

"I’d ask all Americans to say a prayer for these officers and their families.  Keep them in your thoughts.  And as a nation, let’s remember to express our profound gratitude to our men and women in blue -- not just today, but every day," he said at the time.