The answer to this question kind of depends on whether there is already a child support order in place with an accruing arrearage. If there is then you can hire an attorney who can help you get a lien on the properties that the father owns (if he has proper title in the houses and the car). If there is no child support order in place then you would have to establish a child support order. This can get a little more complicated when the father lives in a different state than that of the mother and child. It can also be more complicated when the father is in prison, as many states are changing how they calculate support orders for people in prison. Another resource you may want to try is to contact your local child support agency to see if they can help you establish an order.
There are many important facts left out of this question: (a) where do the children live; (b) where does the mother live; (c) where did the mother and father last live together; (d) is there now or has there been an legal action started to determine parentage of the children (e) has any action been initiated to determine child support or child custody; (f) where were the children born. All of these questions impact on where a proper filing must be made under applicable jurisdictional statutes (the Uniform Interstate Family Support Act applies to child support determinations). Federal law provides that this process may be initiated through the local state family services offices (SRS in Kansas), but the state in which the initial proceedings must occur are determined by the answers to the above questions.
This response is informational only and is based only upon applicable Kansas statutes. This response does not create any attorney-client relation and is not legal advice.