Assistant DA gunned down while getting out of a car.

A manhunt is underway for two suspects after an assistant district attorney was gunned down Thursday outside a courthouse in Kaufman, Texas.

The prosecutor was shot five times around 9 a.m. local time outside the Kaufman County Courthouse, ambushed while getting out of his car, KDFW-TV is reporting.

Sheriff David Byrnes said the killing was an attack on the criminal justice system."This is the next level (of crime)," he said.

The Dallas Morning News is reporting that "authorities with knowledge of the assistant DA's caseload say he had been heavily involved in the investigation of members of the Aryan Brotherhood."

A probe is underway to determine if the shooting is connected to that investigation, the Morning News says.

The victim was pronounced dead at a nearby hospital. The identity has not been released because his family hasn't been notified, Kaufman County Sheriff David Byrnes said.

Security officers and deputies closed nearby streets in Kaufman, a North Texas town of about 6,700 residents less than 40 miles from Dallas. Kaufman schools were put on lockdown.

Kaufman County Judge Bruce Wood said the courthouse is closed today and it would be up to the sheriff to determine when it would reopen.

Wood told the Morning News he saw the victim every day in the courthouse hallways.

"He was revered and he did an outstanding job," Wood said. "We see each other every day. … It's a very small courthouse."

"It's a horrible situation," Wood told the Morning News. "None of us would have ever expected anything like this to ever happen in our county."

The shooting has resulted in warnings elsewhere. WFAA-TV in Dallas says the email below was sent by the Dallas County DA:

"This message is not intended to scare anyone but please be advised. A Kaufman County prosecutor was fatally shot a few minutes ago outside the Kaufman County Courthouse in Kaufman. Two masked gunman are the suspects. They have not been apprehended yet.

Please be aware of your surroundings when leaving the building for your safety. This is probably a isolated incident but until further notice if you plan to work past dark today please be careful and ask security for assistance escorting you to your vehicles if needed. I will keep you informed as to the arrest of the suspects when i am notified. Don't panic but please be aware of your environment when leaving the building."

Kaufman Police Chief Chris Aulbaugh said the shooting would have a major impact on his town and the county.

"Any loss of life, especially someone out there protecting the community, would have that effect," he said.

Contributing: Associated Press