DETROIT—After his partner of three years was gunned down last week while the pair were on duty, Detective David Killian of the Detroit Police Department’s Major Case Squad told reporters Wednesday he was unsure whether he had been close enough to his murdered colleague to single-mindedly pursue the killer for as long as it takes. “Sure, [Detective] Rich [Lerner] was a nice guy, but it’s not like we went out to get drinks with each other at the end of each shift or anything like that—we’d usually just say so long and head home,” said Killian, adding that he and Lerner “never really talked about any personal stuff” and that their relationship, while amicable, was largely centered around day-to-day police work. “Maybe if Rich and I were the kind of guys who brought our families over to the other’s house for the occasional weekend cookout or holiday dinner I’d be willing to do whatever it takes to track down the dirtbags who did it, but that’s just not the case. I can see maybe putting in a solid week or 10 days on this. I’m definitely upset over the whole thing, but I’ve got a pretty big caseload as it is.” Killian said he felt further relieved of the burden of relentlessly tracking down his partner’s murderer after meeting with Lerner’s grieving widow, who told Killian to “do what [he] can,” but not to “make [himself] crazy or anything.”