It is not allowed to hang a picture or keep a picture of any being that possesses a soul. It is obligatory to destroy such pictures. This is because the Prophet (sallallaahu ‘alaihi-wasallam) said,
“Do not leave any image, but [instead] efface it.”  It was confirmed in the hadith of Jabir radiyallaahu ‘anhu that,
“That because the Prophet (sallallaahu ‘alaihi-wasallam) prohibited having pictures in houses.” 
Therefore, all pictures meant for remembrance should be torn to pieces or burnt. However, pictures that are needed out of necessity, such as for official identification purposes and so forth, may be kept.
 Recorded by Muslim.
 Recorded by Tirmidhi and Ahmed. Al-Albani says it is Sahih