"You'd think you would want to be involved if somebody was missing that was close to you, that you would want to help find them, [but] he's not cooperative," Sgt. Tom Nestor of the Pinellas County Sheriff's Office told AOL News.
Rothwell, 35, was last seen Saturday when she left a restaurant in Clearwater with her friend, Donna Scharett.
"We had lunch together at Chili's restaurant, and, about 3:30 p.m., said goodbye in the parking lot," Scharett told AOL News. "That's last time anyone heard of her."
According to Scharett, Rothwell, who had recently left her hotel job to enroll in the Pinellas Police Academy in St. Petersburg, was in good spirits at the time of their meeting.
"She was exuberant. She was more than happy," Scharett said. "She was looking forward to starting a brand-new life as a police officer and outside of her relationship with Dave."
Authorities have not named Perry as a suspect or person of interest in his girlfriend's disappearance, but police say he is considered a "witness."
"We can't consider anyone a suspect when we don't have a crime," Nestor said. "We know she is missing and we believe foul play is involved because it is not typical of her behavior, but we have found no signs of foul play. We are going on family and friends' statements that this is completely out of character, and that is why we are treating this like foul play is involved."
Nestor said that authorities would like to speak with Perry so that they can piece together a timeline but say he has not been responsive. "He's not given a statement [and] he's not returning our phone calls," the officer said.
Perry, 46, is a retired corrections officer. The couple met in November 2007, while Perry was vacationing in Florida. Roughly two months after their meeting, Perry moved from Elmira, N.Y., into Rothwell's Indian Rocks Beach home. In the beginning, the relationship went well, but as time wore on, things changed, Scharett said.
"Kelly is a very private person. She wouldn't tell anybody about all the details of her life, but there was tension," her friend said. "Dave was very controlling and, until she got into the academy, she was a very timid, shy kind of person. Kelly had tried to leave the relationship a few times, but he just weaseled his way around it."
According to Nestor, authorities have never been called to the couple's residence regarding a domestic dispute.
"He or she had not called about fights, physical abuse or anything like that," he said. "We were told by the family and a friend that they were having domestic problems, but not necessarily violent [disputes] because we were not called to that house to take any reports of domestic violence."
Scharett called police Sunday morning and asked them to check on Rothwell after mutual friends told her she failed to show up for a planned get-together on Saturday evening. Repeated phone calls by friends and family to her cell phone had also gone unanswered.
When deputies arrived at the residence that Rothwell and Perry shared, they did not find any sign of the couple, and both of their vehicles were gone. Later that day, deputies located Rothwell's green 2007 Subaru Outback abandoned on a street about two miles south of her residence.
Detectives also located Perry, who had left Florida for New York state. They are uncertain if or when he may be returning.
"The house is full of furniture and their belongings and he has not returned yet," Nestor said.