MESQUITE -- The chief investigator for the Kaufman County district attorney's office, a veteran lawman, broke down in tears Thursday as he remembered his former boss."We will not stop pursuing justice," Bruce Bryant said from the pulpit of the First Baptist Church of Sunnyvale."We will not give up the good fight. We will not stop doing God's work. We will pause only to celebrate the lives of those we have lost, but we will not stop."District Attorney Mike McLelland and his wife, Cynthia McLelland, were shot to death in their home near Forney on Saturday. On Thursday, they shared a single flag-draped casket inside the church in Mesquite. Her body was cremated and the ashes placed in an urn in the casket.Surrounding the casket were mementos of their life together -- portraits, a soldier's jacket from Mike McLelland's Army service and a quilt to commemorate Cynthia McLelland's favorite hobbies.Honor guards stood at attention as dozens of other law officers sat in the audience. Officers in a balcony behind the stage could be seen raising white-gloved hands to their eyes during the service.Among the hundreds of mourners were public officials including Gov. Rick Perry.McLelland had spoken to many of the same people two months ago after Mark Hasse, one of his prosecutors, was gunned down near the Kaufman County Courthouse.No arrests have been made in either case. The reward for information leading to a conviction has reached $200,000.Perry said he had spoken to McLelland weeks earlier at the state Capitol. Perry mentioned both McLellands' public service -- Mike as a 20-year Army veteran and district attorney, Cynthia as a psychiatric nurse who worked at the Terrell State Hospital.They knew the dangersPerry said both were aware of the dangers of the district attorney's job."It's an art form. It's a calling, and one of the more difficult ones, I imagine," Perry said in a quiet, sometimes halting voice.Kaufman County Judge Bruce Wood said he got to know Mike McLelland while the two were campaigning for office three years ago."I knew immediately how intelligent he was," Wood said. "But he was quite a character too."In the months after Hasse was killed, McLelland began to carry a gun everywhere and took extra caution when answering his door. He told The Associated Press in an interview shortly before his death that he was warning his employees that they needed to be more cautious as well."The people in my line of work are going to have to get better at it," he said of dealing with the danger, "because they're going to need it more in the future."Mike McLelland had been married twice before, and Cynthia had been married once. They had five children between them.Christina Foreman said both her mother and stepfather "loved every minute" of their public service. She challenged the audience to stand up for what they believe in."They would have done it exactly the same way, because Mike believed in making a difference," Foreman said.Foreman told the audience they had a responsibility not to let fear stop them from fighting to do right thing.She said she believed that her mother and stepfather had prepared her for this moment, when she and her siblings must go on without them."The right thing is never easy," Foreman said. "And he knew that. And he stood up anyway."State doubles rewardAt a news conference Thursday morning in Kaufman, Perry urged anyone with information about who killed the McLellands and Hasse to contact law officersThe state added $100,000 to match the reward offered by Kaufman County Crime Stoppers after Hasse was slain."We will not let this cower us. Texas is a law-and-order state and we will track down and punish those who have committed this crime," Perry said.He was flanked at the news conference by FBI agents, sheriff's officials and other law enforcement. Flags were at half-staff Thursday outside the Kaufman County Courthouse, which closed for the afternoon so employees could attend the service.Perry said it was "very premature" to speculate on whether a particular group is responsible.The FBI has launched billboards in five states encouraging people to come forward with information about the slayings. The billboards in Texas, Oklahoma, Louisiana, Mississippi and New Mexico to encourage tipsters to call Crime Stoppers.The space was donated by the Outdoor Advertising Association of Texas.