"It is with a very heavy heart that I have to pass on devastating news to all of you. At approximately 3:30 this morning, Mario died. Carrie and his 4 amazing children were able to be with him. I am at a loss for words as we try to process this. Please pray for Carrie, his kids and our entire family," said the post, written by Herrera's sister-in-law, Melissa Wood, on a CaringBridge page.

In a statement, LPD said it was "devastated by the loss of one of our most outstanding police officers."

"Mario was an exceptional investigator, a selfless teammate, and a tireless public servant. Empathetic, kind, and utterly committed to serving victims and protecting his community, Mario was an exemplary human being who just happened to be a Lincoln police officer.

"Our thoughts and prayers are with them (the family) as they grieve his death. Please continue to respect their privacy during this difficult time," the statement said.

The department said it will hold a news conference Tuesday morning.

Mayor Leirion Gaylor-Baird said in a statement: "Sadness does not begin to describe fully our community's sense of loss with the passing of Investigator Mario Herrera.

"Our hearts are with his wife, Carrie, and their four children, and we remain forever grateful for their family's profound sacrifice in service to keeping our community safe," she said.

Gov. Pete Ricketts ordered flags in the state to fly at half-staff beginning immediately until sunset Friday, which is Patriots Day, in honor of Herrera.

“Susanne and I were devastated to learn of the passing of Investigator Mario Herrera,” Ricketts said in a news release. “Investigator Herrera’s service and sacrifice will never be forgotten. I also want to thank people across the state who stepped up to support the Herrera family in the midst of this terrible tragedy. From holding prayer vigils to donating blood, the community’s response was powerful and inspiring. Now more than ever, it is critical for all of us to come together and support the men and women who put on the uniform and risk their lives every day to help keep our communities safe.”

Herrera was shot Aug. 26 while members of the Metro Area Fugitive Task Force, the department's gang unit and the criminal division were serving a warrant at a house near 33rd and Vine streets after getting information that 17-year-old Felipe Vazquez — who was wanted for second-degree assault in connection with Edward Varejcka's stabbing death in March — was there.

Vazquez and Orion Ross, 19, allegedly broke out a window of the house and escaped, firing shots at Herrera and other officers. Vazquez and Ross have been charged with escape using force or a deadly weapon, and Vazquez faces an additional count of possession of a stolen firearm and no doubt more charges in wake of Herrera's death.

Lancaster County Sheriff Terry Wagner, whose department is leading the investigation into the shooting, said last week that evidence showed that Vazquez fired the shot that hit Herrera.

Herrera, who was there in a number of capacities, including as an interpreter, was struck in the torso. He was not wearing a ballistic vest.

He was initially taken to Bryan West Campus and then was transferred to the University of Nebraska Medical Center in Omaha, where he had been in critical condition ever since and had undergone numerous surgeries.

There had been an outpouring of community support for Herrera and his family. A GoFundMe page had raised more than $126,000 as of Monday evening. People also showed up in droves to donate blood, and residents who live in his neighborhood tied blue ribbons around trees.

LPD said on its Facebook page that officers will be draping their badges in honor of his memory.

Herrera is the first LPD officer to die in the line of duty since 1968, when Officer George Welter died in a motorcycle crash while responding to a call. Before that, the last time an LPD officer was killed in the line of duty was in August 1967, when Detective Paul Whitehead was shot after stopping a suspicious vehicle.

The last law enforcement officer in Lancaster County to be killed in the line of duty was Lancaster County Sheriff's Deputy Craig Dodge, who was shot in March 1987 while responding to a domestic violence call in Hickman.