Let the vertices are

There are many ways to show that the points vertices of ractangle.

In this casae we use

AC and BD are diagonals of rectangle,that AC BD bisect each other and the diagonal AC ,BD are equal.

We need to prove mid point of AC and BD are equal.

Thus,

AC = BD

Therefore, (-4,-1) , (-2,-4) , (4,0)  and (2,3) are vertices of a rectangle.----