If I were to start a new venture focused 100% on the law enforcement market, these skills would be extremely valuable. However, I'd probably prefer to partner (in equity) instead of paying cash. Perhaps taking on this kind of person as an advisor.
Assistance earlier in the product lifecycle would be useful too. For example, right now I have vague ideas about how deep learning image and video processing could be applied to law enforcement, but I'm not familiar enough with specific use cases to build something. It'd be valuable to talk with a domain expert about (1) what's now possible with the technology and (2) specific problems such tech could solve in the industry.
Once the technology has product/market fit, catalyzing distribution via warm intros to prospective clients would also be super helpful. If I know we have something people want, I'd spend money to get more customers so long as the lifetime value math worked out.
Hope that helps!