Patrick Maloney is a police officer. More specifically Patrick Maloney is a detective in the police department.
"As the wife of a detective, she knew what the punishment would be."
The story is not clear about whether or not Patrick is a good detective or not. Regardless of his ability to do his job, Patrick was probably a well liked detective at the police station. The detectives that are sent to Mary Maloney's house to investigate the murder all seem genuinely concerned and motivated to find the murder weapon and the murderer. They also stay for dinner. I feel that if they didn't like Patrick, they would have done their due diligence and left as quickly as possible.
Other information about Patrick is discovered near the beginning of the story. He's either blind to Mary's single minded devotion to him, or he's just a flat out jerk. I think it's the latter. She obviously adores him like no other. She's also 6 months pregnant with his baby, yet he still announces in casual conversation that he's leaving her.
"So there it is," he added. "And I know it's a tough time to be telling you this, but there simply wasn't any other way. Of course, I'll give you money and see that you're taken care of. But there really shouldn't be any problem."
No problem? I guess he didn't anticipate his wife's skill with frozen meat.