Why is Gambia's President Barrow scared of his military?

Gambian President Adama Barrow wants Senegal to send over 600 troops to his country ahead December elections. This is in addition to the Senegalese forces already there as part of the ECOWAS peace mission deployed in 2017. DW's Jane Nyingi spoke to Omar Wally in Banjul and first wanted to know if the Gambian army is capable of handling its security issues.