diff --git a/benchmarks/imaging_ecal/scripts/draw_cluster.py b/benchmarks/imaging_ecal/scripts/draw_cluster.py
index def39c45fcaba6f080e2dde5adb6688312e1e9ca..69b641ecb7fee402e10c2a9b9036dc759a82cdf2 100644
--- a/benchmarks/imaging_ecal/scripts/draw_cluster.py
+++ b/benchmarks/imaging_ecal/scripts/draw_cluster.py
@@ -5,6 +5,10 @@
 
     Author: Chao Peng (ANL)
     Date: 04/30/2021
+
+    Added true decaying particles on eta-phi plane projection plot
+    Author: Jihee Kim (ANL)
+    Data: 08/06/2021
 '''
 
 import os
@@ -144,10 +148,10 @@ if __name__ == '__main__':
     df['eta'] = -np.log(np.tan(df['theta'].values/1000./2.))
 
     # Read all mc particles
-    ########################
     dfallmcp = get_all_mcp(args.file, args.iev, 'mcparticles2')
     # Select decaying particles
-    dfdecaymcp = dfallmcp[dfallmcp['g4Parent'] == 1.0]
+    dftemp = dfallmcp[dfallmcp['g4Parent'] == 1.0]
+    dfdecaymcp = dftemp.copy()
     pdgbase = ROOT.TDatabasePDG()
     for iptl in [0, len(dfdecaymcp) - 1]:
         infoptl = pdgbase.GetParticle(int(dfdecaymcp['pid'].iloc[iptl]))
diff --git a/benchmarks/imaging_ecal/scripts/utils.py b/benchmarks/imaging_ecal/scripts/utils.py
index 00bd51dc54af8e678cab31a24559709911b54e2a..19f3722d1409ae7413949b01935198119f8223ab 100644
--- a/benchmarks/imaging_ecal/scripts/utils.py
+++ b/benchmarks/imaging_ecal/scripts/utils.py
@@ -104,7 +104,7 @@ def get_all_mcp(path, evnums=None, branch='mcparticles2'):
         events.GetEntry(iev)
         # extract mc particle data
         for ptl in getattr(events, branch):
-            dbuf[idb] = (iev, ptl.psx, ptl.psy, ptl.psz, ptl.pdgID, ptl.status, ptl.g4Parent, ptl.vex, ptl.vey, ptl.vez)
+            dbuf[idb] = (iev, ptl.ps.x, ptl.ps.y, ptl.ps.z, ptl.pdgID, ptl.status, ptl.g4Parent, ptl.ve.x, ptl.ve.y, ptl.ve.z)
             idb += 1
     
     return pd.DataFrame(data=dbuf[:idb], columns=['event', 'px', 'py', 'pz', 'pid', 'status', 'g4Parent', 'vex', 'vey', 'vez'])