Do I need a lawyer to walk away from our mortgage. Our house has depreciated 100,000 we owe more than it is worth. We can no longer make the payment due to higher taxes and ins and loss of income.

You don't need a lawyer to walk away from a mortgage, but you need to know what is best in your situation. Has your home been 'for sale'? Why don't you Google, 'default on mortgage' in your state and see what comes up? The 'loss of income' would appear to be the most pressing issue, and it makes little sense to continue bailing out a sinking boat. At some point the home will be sold, probably for less than what is owed, and the lender may want you to payoff the balance. At that point, you may want to consider Chapter 7 or Chapter 13. Bankruptcy Chapter 7 Personal Consumer Creditors File and Bankruptcy Chapter 13 Debt Payment Retain Assets

no, you may need one latter in court if it comes to that, or in filing bankruptcy latter if needed. For example, do you have the income to pay for the mortgage, if no, why did you take the mortgage out ?
If you can afford the mortgage, is the only reason you don't want to keep paying is the lower value of the home?