Pursuit-Evasion

nc = 15; nr = 3; 
cx = Table[ToExpression[StringJoin["cx", ToString[i]]], {i, 1, nc}]; 
cy = Table[ToExpression[StringJoin["cy", ToString[i]]], {i, 1, nc}]; 
rx = Table[ToExpression[StringJoin["rx", ToString[i]]], {i, 1, nr}]; 
ry = Table[ToExpression[StringJoin["ry", ToString[i]]], {i, 1, nr}]; 
coordList = Flatten[{Transpose[{cx, cy}], Transpose[{rx, ry}]}]; 
cspeed = 1; 
rspeed = 1.1; 

eqns = Flatten[
        {Table[
          {{Derivative[1][cx[[i]]][t], Derivative[1][cy[[i]]][t]} == 
              cspeed*Normalize[Sum[{rx[[j]][t] - cx[[i]][t], ry[[j]][t] - cy[[i]][t]}/((cx[[i]][t] - rx[[j]][t])^2 + 
              (cy[[i]][t] - ry[[j]][t])^2), {j, 1, nr}]], 
            cx[[i]][0] == RandomReal[{-30, 30}], 
            cy[[i]][0] == RandomReal[{-30, 30}]
          }, 
          {i, 1, nc}
         ], 
         Table[
          {{Derivative[1][rx[[i]]][t], Derivative[1][ry[[i]]][t]} == 
              rspeed*Normalize[Sum[{rx[[i]][t] - cx[[j]][t], ry[[i]][t] - cy[[j]][t]}/((cx[[j]][t] - rx[[i]][t])^2 + 
              (cy[[j]][t] - ry[[i]][t])^2), {j, 1, nc}]], 
            rx[[i]][0] == RandomReal[{-5, 5}], 
            ry[[i]][0] == RandomReal[{-5, 5}]
          }, 
          {i, 1, nr}
         ]
        }
       ]; 

soln = NDSolve[eqns, coordList, {t, 0, 200}, MaxSteps -> 200000, PrecisionGoal -> 2][[1]]; 

coordListFn[t_] := Flatten[Table[{coordList[[i]][t], coordList[[i + 1]][t]}, {i, 1, 2*(nc + nr), 2}]]
cops[t_] := Evaluate[coordListFn[t][[1 ;; 2*nc]] /. soln[[1 ;; 2*nc]]]
robbers[t_] := Evaluate[coordListFn[t][[2*nc + 1 ;; 2*(nc + nr)]] /. soln[[2*nc + 1 ;; 2*(nc + nr)]]]

Manipulate[
  Show[
    ParametricPlot[
      {cops[t], robbers[t]}, {t, 0, tmax},
      PlotRange -> All, PlotStyle -> {Darker[Red], {Darker[Green]}}
    ], 
    ListPlot[
      {Partition[cops[0], 2], Partition[robbers[0], 2], Partition[cops[tmax], 2], Partition[robbers[tmax], 2]}, 
      PlotStyle -> {Directive[PointSize[Medium], Black], Directive[PointSize[Medium], Black], Darker[Red], Darker[Green]}
    ], 
    Axes -> False
  ], 
  {tmax, 0.001, 200, 1.5}
]