Police in Iowa have arrested a 47-year-old man who they claim admitted to killing his wife - a respected scientist - by sneaking up on her and stabbing her with a knife from their own kitchen. The Coralville Police Department said that Amber Nicole Martin, 41, a medical laboratory scientist supervisor of microbiology working at the University of Iowa Health Care, was found stabbed to death on Friday, January 16. Her husband, James Fuller Martin, has been formally charged with first-degree murder, according to The Gazette. James had allegedly told police that he stabbed his wife after spending the hours leading up to the murder planning out exactly how he would do it, the paper reported. It was unclear Tuesday, January 20, if James told police the reason why he killed his wife. Coralville Police were sent out to the couple's home Friday morning after 911 calls came in about a possible stabbing, the Gazette reported. Murdered Indiana Mom Filed for Protective Order on Christmas Before Death Cops arrived to find Amber with multiple stab wounds. They tried reviving the unresponsive woman but ultimately declared her dead at the scene. The stabbing unfolded at approximately 6:40 a.m., when James told police he "retrieved a kitchen knife and surprised the victim as she exited another room," according to reports. Amber Nicole Martin Courtesy of Amber Martin/Facebook Amber had previously worked at Quincy Medical Group as the Microbiology Coordinator. James was also listed online as having worked at Quincy Medical Group as the Hematology Coordinator. People spoke to Amber's supervisor at work, Connie Floerchinger, who said that she was "a very good leader" who "fit into our team very quickly." "Our technologists all thought very highly of her," Floerchinger told People, adding Amber loved her job and workplace. "She and I were talking about succession planning, and I told her that I could see her taking my position when I retired. She walked to my doorway, and I looked back at my computer. She turned around and said my name and when I looked up, she gave me the hand heart sign. That was Amber in a nutshell." James Fuller Martin Johnson County Iowa Jail Quincy Medical Group employee Ann Ostermiller opened up about the couple to Muddy River News, saying that "Amber was such a wonderful woman. She was vivacious, kind, and loved by all her coworkers." She added that "Jim was quieter and more reserved." "This murder is beyond the comprehension of those that knew them when they worked at QMG," offered Ostermiller. "They seemed to be such a close and loving couple. I cannot imagine what transpired to change their relationship so much." Man Told Son That He Stabbed 'Cheating' Wife, 'Sat with Her' as She Died The investigation into Amber's death remains active and ongoing. Officials have asked that anyone who was in the area at the time of the murder contact the Coralville Police Department at (319) 248-1800. Plea and attorney information for James was unavailable on Tuesday, January 20. Us Weekly was unable to reach anyone at the Coralville Police, the University of Iowa Health Care and Quincy Medical Group for comment. class="c-link" href="tel:18007997233″ target="_blank" rel="noopener noreferrer" data-stringify-link="tel:18007997233″ data-sk="tooltip_parent">1-800-799-7233, or go to thehotline.org. All calls are toll-free and confidential. The hotline is available 24/7 in more than 170 languages.