Dallas police shooting victims: These are the names of the officers killed

Twelve police officers were shot and five of them killed by snipers near a peaceful protest in Dallas last night, making it the deadliest day for law enforcement since the terrorist attacks on Sept. 11, 2001.

President Barack Obama called it a "vicious, calculated and despicable attack," and vowed to see that "justice will be done."

The slain officers, gunned down as they monitored the nonviolent demonstrations, served the Dallas Police Department and the Dallas Area Rapid Transit agency. Here are their names.

1. Brent Thompson, 43

Brent Thompson joined DART in 2009. "Brent was a great officer," DART chief James D. Spiller told MSNBC on Friday. "He was an outstanding patrol officer as well as a rail officer."

Thompson had just wed another DART officer, according to WFAA reporter David Goins. Spiller, who recently spoke with Thompson, said the officer "was in great spirits from his recent marriage."

Prior to joining DART, Thompson worked for DynCorp International as an as an International Police Liaison Officer in Southern Iraq, according to his LinkedIn profile. He was "responsible for the day to day operations conducted by our American police officers who trained and mentored the Iraqi Police."

Thompson was the first DART officer killed in the line of duty.

PHOTOS: Dallas shooting victims

This post will be updated as more names are made available.